Prince fans are being warned he and his band may not appear at the "aftershow" events promoted as part of his UK tour.
Tickets to the "official aftershow" have been priced at £75 and £25
Parties at the Indigo venue follow his concerts at London's O2 arena, but fans say sometimes he fails to go to these, or has played for only a few minutes.
Prince's website now says that when there are arena gigs on consecutive days, "the band usually opts to rest" instead of appearing at Indigo.
A spokeswoman for Prince said it was "never guaranteed" he would appear.
"What's always been up on the official website was that Prince's band would play most nights, and on any given night the Purple One could come.
"But every night was going to be different and special," she told the BBC News website.
The arena's stage is the symbol to which Prince changed his name (photo by Andrew Buchan)
"For instance, the other night, his opening act Beverley Knight took to the stage for a long, late-night jam session with Prince on the guitar, which was a very special surprise for the crowd."
Many fans who booked tickets to the concerts in the main arena received promotional e-mails from agency Ticketmaster, highlighting the addition of the "aftershow" events to the tour schedule.
The agency's website promoted the "aftershow" as "the white hot place to hang for those still in need of some serious grooves".
Tickets were priced at £75 and £25, whereas the main arena show was £31.21 per seat, the figure being a reference to recent Prince album 3121.
Ticketmaster also stated: "Please be aware that Prince and the band are not guaranteed to perform, but as we all know with these cats - expect the unexpected."
Prince's spokeswoman said Knight's set was "a very special surprise"
Adding to the confusion, a notice was placed on Prince's own site saying that he would not be playing at Friday night's "aftershow" - although then he did appear after all, with soul singer Knight.
However, fans on chat forums such as prince.org and housequake.com have alleged that warning messages were not prominently displayed when they booked tickets.
They said they had the impression that all "aftershow" events were further Prince concerts.
Some people claimed they had been contacting Ticketmaster to request refunds.
The star has been playing sets of about two hours in length in the main O2 arena, running through many of his hits, including Purple Rain, Alphabet Street and Kiss.
The star prepared 150 songs so he could rotate the setlist nightly
He said he had prepared 150 songs for his musicians, who include Maceo Parker, formerly a saxophonist in James Brown's band.
Neither Ticketmaster nor the O2 arena could be reached for comment, while promoter AEG referred calls to Prince's PR representatives.
We asked for your experiences of Prince's "aftershow" events in the O2's Indigo venue, and whether they had lived up to your expectations.
Here is a selection of responses received.
I think the main point is that Prince's official website announced on Friday that he would not play at the aftershow, but there was a strong chance he would play Saturday. Therefore many people, including myself, who attended the Friday and Saturday main shows took this to be the truth and didn't attend Friday's aftershow, but did buy tickets for Saturday. In fact, he played Friday and didn't show on Saturday. No-one expects 21 mains shows and 21 aftershows where he plays for hours also, but it would be nice to not be misled by his own official website. Just let us know beforehand if he's turning up is all I ask - and get it right.
John, Swindon, UK
I had tickets for Saturday's aftershow. After waiting in the queue for over an hour to get into the Indigo, we were told that Prince wouldn't be performing or indeed attending. They told us this just after the last tube had left and with only 10 minutes before my last train back to Brighton. I had an expensive taxi to Victoria and a long three-hour wait at Gatwick until I could get the first train back to Brighton. WHAT A SHAMBLES. And all we can do apparently is exchange the tickets for another aftershow, which will mean trying to buy tickets for the actual show as well.
Simon, Brighton, UK
I paid £25 for two tickets on 4 August and specifically asked what time Prince was coming on - I was told by ticket office staff it was 1 am. I waited and waited, listened to a poor tape recording of Prince's new album for three hours with no announcement by Indigo to say he wasn't playing - they were happy to let us just sit there and wait. I was very disappointed. If we had been warned there was a chance he might not have come out then fine, it would have been a risk for us to take - but we paid our money on the basis of ticket staff saying he was playing. Ticketmaster blame AEG. I've been waiting for almost a week for them to respond to my complaint. If they don't respond to the BBC then what chance have I got?
Lesley Boyle, Billingham, UK
I went to see Prince at the O2 on Friday and had tickets for the aftershow at the Indigo. After a brilliant set by Beverley Knight, Prince's band and the man himself came on stage at around 2 am, and was jamming with them 'til 4 am. The show was as much about the band as him. In fact his vocal output was limited. Was worth every penny of the £25 ticket cost, though. The venue is small and intimate and it was the perfect end to an already fantastic night. All that said, I was fully aware beforehand that there was no guarantee Prince would be perform.
Deb, Doncaster, UK
I had an EXCELLENT time at the first aftershow on 1 August. Prince did appear for over an hour, but I was under no delusions that such an appearance was guaranteed. The fault here is not Prince's but some peoples expectations, which are based on nothing but fantasy. I challenge any of these complainers to show where it was written that Prince was guaranteed to play these aftershows. If they have a genuine complaint, they should be able to provide evidence to substantiate it.
Antony Hitchin, Chelmsford, UK
Every Prince fan knows to expect the unexpected. Friday, when he should he would definitely NOT play, the man ended up playing for two hours with Beverley Knight and was one of the greatest I've ever seen him play. No other artist could pull off a two and a half hour show like Prince let alone contemplating another long show until the early hours - fans should be thankful Prince has camped out in London for two months and quit complaining.
Gavin Kingsley, London, UK
Prince's aftershow performances are legendary. In the past they were always much more ad-hoc affairs, but any fan lucky enough to wrangle his or her way into one was usually assured of a more intimate set featuring lesser-known fan-oriented material and improvisation, in a smaller venue. This time around it appeared as if the arrangements were to be more formalised, which seemed like a change for the better. Unfortunately though, when tickets went onsale for "Prince - the Official Aftershow" at Ticketmaster there was no warning that fans were paying for access to the Indigo2 bar only, and that there was no guarantee of any performance. Hopefully Ticketmaster and AEG will now start to take the complaints seriously and refund tickets to people who found themselves having paid so much money for the dubious honour of sitting in an overpriced bar for four hours.
Ian Kiigan, Dundee, UK
Ticketmaster never advised us Prince might not appear, it's been advised later. Also the show's name is clearly "Prince - The Official Aftershow". We bought tickets online - we are still waiting the tickets and we've already paid, so any advertising written on them is useless. If he doesn't appear at any one of the aftershows, we will feel cheated and will complain at the box office for a refund. This has been done totally in bad faith to rip us off.
Elia & Bernardo, Spain
Get a grip. Prince has kept his ticket prices down and sometimes plays two long shows and you're still moaning?! Let the man have a rest, he can't do it night after night. He is getting on a bit, y'know.
Mick Hunter, Leeds, UK
I flew back "'home" on Thursday night to catch the show on Friday at the O2 with a few friends. Beverley Knight was performing - about 45 minutes into the show, Prince and his full entourage appeared on stage to perform with Beverley. Judging by her reaction this was not in the script. She was very shocked and grinning like a Cheshire cat. This continued and just after 2 am - more or less a real Prince show with more hits, cover versions and jamming until he went off stage at 3.25 am. I did hear that Prince has not showed at some of these aftershow events, but that is the beauty and agony of someone like him - expect the unexpected!
Dave, Lund, Sweden
I was at the O2 last weekend for a concert in the Indigo (not the after-show party - an earlier show, different artist) and had to collect my tickets at the box office. Everyone in front of me was buying after-show tickets for Prince and the box office staff were very clear that Prince may or may not show. I know because it took 15 minutes to queue while folks deliberated over whether or not to buy. By the way, I saw a wicked evening of bluegrass with Ricky Skaggs!
Anne, London, UK
My husband and I bought tickets from the box office for 3 August. Before we purchased them I asked the seller if Prince would definitely be there - he told me Prince would be playing an hour-long set. We queued at Indigo for an hour and a half. He did not show - instead Dr John came on! We waited til 4 am, then when we asked staff, we were told Prince had left. We then waited for another hour for a taxi, got back to our hotel at 5.30 am and had to make it to the airport for a 7 am flight. We stayed up all night for nothing. The way we have been treated is just shocking - I have been on to the O2, Ticketmaster etc by phone and e-mail, and as yet no-one has got back to me about my refund. What happened ruined my whole trip - instead of looking back with happy memories, it's just sad ones.
Bridget, Glasgow, UK
Friday [when Beverley Knight played] was one of the best nights of my life. I didn't expect him to play, I just went to have a dance and maybe catch some quality musicians jamming. Not knowing what was going to happen really added to the excitement of the night - I can't stop smiling when I think about how lucky I was to be part of such an amazing show.
Jules, Midlands, UK
I'm just happy he's playing his hits... the man works hard enough. A show with old and new material should be enough, surely!
Steve, Brighton, UK
Just so everyone knows, he has always had afterparties where he is not present. Make sure you know what you are getting into! Myself being a long time fan (not just Purple Rain freaks) know that he sometimes shows and at others he doesn't. Chances we have all been taking!
John Nelson, Janesville, Wisconsin, USA