Touts have started to sell tickets for the Diana memorial concert at hugely inflated prices.
Proceeds will go to charities Diana supported
Offers of seats at more than five times the £45 face value were on the internet before they were officially available.
Internet auction site eBay had dozens of tickets on sale within moments of the box office closing but it said such auctions were being removed.
The first 22,500 tickets for the concert featuring Sir Elton John and Duran Duran sold out within minutes.
Organisers had attempted to discourage touts by limiting buyers to four seats per application.
A spokesman for eBay said: "In view of the unique and commemorative nature of the Concert for Diana event and as a mark of respect for the memory of the late Diana, Princess of Wales, eBay has decided to not allow the re-sale of tickets to this event on the site."
The site also promised to remove an advert which directed people to the site when they entered "Diana tickets" into a search engine.
Tickets have been offered at up to £500 for two
But many people were unhappy that they had been left empty handed while others looked to make a big profit.
Steph Johnston of Perth, Scotland, said: "It made me very angry, I was online at the right moment, I'd made time to wait.
"Being in the military I met Diana, I have met many of the Royals and I queued to see the Queen Mother's coffin.
"I thought this would be a great occasion to remember her but seeing the tickets being sold off for two or three hundreds pounds just rubs salt in the wound."
Online ticket trader My Ticket Market suspended its sales of concert seats after youth charity Centrepoint refused to accept its offer to pass on profits.
Centrepoint's chief executive Anthony Lawton told BBC Radio 4's PM programme: "It's absolutely not in the spirit of this concert.
"We are not going to give succour to the idea of a secondary market and people making money out of the tickets."
The line-up, which has not been revealed in full, so far includes Joss Stone and hip hop artist Pharrell Williams.
The event, which marks 10 years since Diana's death, will take place at Wembley Stadium on 1 July next year.
Sir Elton John
Andrew Lloyd Webber
English National Ballet
Phone lines and internet booking for the first release of seats opened at 0900 GMT and closed 20 minutes later.
The concert has been organised by Princes William and Harry who said they wanted it to be "the best birthday present" for their mother.
William added: "We wanted to have this big concert full of energy, full of the sort of fun and happiness which I know she would have wanted."
Proceeds from the concert will go to a number of charities Diana supported.
It is expected another 10,000 tickets will go on sale to the general public next year, although numbers have yet to be finalised.
There is also to be a memorial service for the two sides of Diana's family on 31 August, the anniversary of her death.
I was online at 3am USA time (9am GMT). I was very disappointed and frustrated not to be able to get tickets. I am an expat living in the USA and am planning to return for an English holiday next year. E-bay is doing a very honourable thing by banning the sale of tickets by touts. I will keep trying in the New Year should any more go on sale.
Jackie Cook, Houston, Texas, USA
I had no problem at all, and bought my four tickets within 2 mints of 9am. It all seemed to go amazingly smoothly to be honest....
Jo Smith, Bristol
I was online from 8.35 this morning, refreshing the screen constantly from about 8.55, at 9.01 the screen became available to buy tickets and I was put in a queue for only 7 minutes, was able to buy 2 tickets with no problems. If it sold out in 20 minutes what did people expect?!
Charlee, Exeter, Devon
I was on line promptly at 9 o'clock and after about 10 minutes wait was connected and put in my order for 2 tickets. I lost the order however when the site would not accept my (British) credit card because it happens to be registered at an Italian address. The delivery options did not include addresses outside the British Isles - hardly very fair.... I tried again immediately but then of course the tickets were sold out.
Chris Hogan, Italy
I was lucky to get hold of 4 tickets at 9.20am. However, I agree that it is unfair that people are re-selling tickets at such ludicrous prices. It is unfair for the people who have a genuine interest in going to the concert.
I had no problem at all. I sat refreshing my PC at 08.59 and went straight through to purchase tickets. I'm now the proud owner of 4 tickets that I have no intention of selling.
Samantha Friar, Croydon, UK
I managed to get through no problems and purchased four tickets. I am not sure now whether I can be bothered to go having heard the list of acts performing. Very disappointing.
Sinep Longfellow, Romsley, Halesowen
Managed to get tickets, went through at 9:05. Got 4 - but it was a race against time, each section gave you a time limit to finish each section before they offered it to the next person.
Got 4 tickets - perfect Xmas presents for the family. Got lucky on the internet I suppose.
At 9am the website slowed down enormously but the tickets didn't become available until 9.01; I was constantly refreshing until the ticket option was available. I waited, as it instructed me, in a queue for about 10 minutes and then was able to order 4 tickets with no problems at all. I think the servers took a hammering as soon as they were open and effectively those, like me, sitting there waiting for them took all the tickets very quickly. The phone service was a waste of time - I had two phones calling continuously, only busy messages.
Logged online this morning at 9:00am, and was able to get 2 tickets right away, transaction complete by 9:03am. Could not have been easier. Really looking forward to the concert.
Greg, Dollar, Clackmannanshire
For the full 20 mins I was trying both online and via the phone to get through - I did eventually get through on the phone to the automated service, only to be disconnected and put through to from Ticketmaster who could not help me! He re-gave me the concert number whilst muttering, "This keeps on happening this morning........" No tickets to be had for me, and very disappointed I am too!
I was on the Ticketmaster website at 9am and had to hold for 20 minutes and still couldn't get 2 tickets. It does not seem fair that people can buy more than 2 tickets as its obvious they only want to personally profit!!
Lyn Cartwright, Stoke on Trent
I have had allocation 5 times this morning of 4 tickets but every time I tried to complete the sale it kept telling me that I had not ticked the box accepting terms and conditions when clearly I had. So really angry and disappointed to have failed in securing a ticket at all!
Pauline Lightfoot, Romsey
I was on the internet constantly and kept being told when I reached a certain point that my credit card details were incorrect and my daughter was getting exactly the same message. I can't see that we were both getting it wrong. Makes me wonder what the real problem was. Very disappointing.
Jo Riddle, Old Windsor
Why are eBay allowing reselling of tickets for other events but not this one? It should be disallowed in all cases. Yesterday I tried to buy some tickets for Ricky Gervais but they sold out within hours. So I then checked on eBay and lo and behold there's lots of Ricky Gervais tickets for sale and bids are way above the ticket price. This is pure profiteering and the performer is not gaining anything from it. Also true fans are missing out or having to pay over the odds for a ticket.
Peter New, Newbury, Berkshire