A nine-month investigation by BBC reporters working undercover in a leading British bank has revealed a culture of ruthlessness and lies which will shock their customers.
Barclays says that it treats customers fairly
With a touch of glee, my bank trainer told a classroom full of call centre trainees that he "loved" getting customers complaining about bank charges.
"They'd phone up, start crying and blaming you and telling you their kids are going to starve. And I'd be like, 'I don't know you - I don't care'. I was just thinking 'you're not getting it back'. I was a right git."
This was an early insight into how life might be working inside a Barclays call centre in Doxford, Sunderland.
I have been undercover in one of the top British banks for the last five months - and it has been an extraordinary experience.
I've seen customers misled, lied to and treated with contempt.
I've seen people charged for financial products they neither asked for or knew they had.
And in a separate investigation I've also seen evidence of bank employees working with criminals to commit fraud.
All this in an industry which claims it operates to the highest standards of care and trust.
At the call centre in Doxford I was one of 1,800 people who work day in, day out selling Barclays' products.
Staff often gave the impression that customer service lay at the bottom of everything we did. But that wasn't always the case.
The lie began the minute we got through to the customer. "Hello, my name is Amanda Egbujo and I'm an account consultant."
I wasn't anything of the sort of course. I was employed as a "sales adviser". But as one of my colleagues told me: "You have to lie a lot" if you want to get into the call for long enough to start selling.
Yet banks are supposed to operate under strict rules imposed by the Financial Services Authority to prevent customers being misled.
But this cynical attitude to sales - and to customers - permeated every aspect of my work with the bank - both in the call centre and later when I transferred to a high street branch of the bank in Guildford, Surrey.
As my trainer Simon Pickergill said: "I hate it when they say the customer is always right. It's just ridiculous. Someone was stoned when they made up that policy."
Remember this isn't just anyone, this is a man who Barclays had chosen to teach us, the bank's new staff, how to behave.
Barclays, like most banks, has a system of targets and bonuses to encourage its staff to sell.
I saw the effects of the ruthless target-driven environment.
In just four weeks in my branch, I saw one of my colleagues break down in tears because of the pressure to sell and I heard about another from a different branch being suspended, accused of a series of misdemeanours - including moving more than £200,000 from one customer's account to another, without permission, purely so he could get commission.
Mis-selling seemed to be rife.
One manager admitted that the bank's "Additions" accounts are one of the "most mis-sold" products in the bank.
Additions' accounts can cost around £150 a year, in exchange for which the customer gets a range of benefits.
They are worthwhile for some customers, but even more worthwhile for the bank - raking in tens of millions of pounds a year.
To encourage us to sell them we are paid a bonus of £10 for each one we sell.
The problem is that if the customer already has an account with us they don't have to sign for the new account.
And as the manager explained it often happens that staff, under pressure to sell, simply give the customer an Additions account without telling them and many may not notice the extra charge on their account for months.
Indeed just a week after that manager described this to me, I was there when an angry couple came into my branch complaining that just that had been done to them.
Just a few weeks ago Barclays announced record profits of £7 billion.
What I saw there makes me feel very uneasy about how they made at least some of that money.
In response to our allegations Barclays Bank said: "We are not in the business of encouraging or condoning mis-selling or inappropriate sales in any way whatsoever, and we stamp on that when we find it because it is completely inappropriate behaviour for a bank.
"We pride ourselves on being a responsible institution that puts its customers first."
It added: "People know we are a good bank, we're trustworthy, we do the right thing, we treat people with respect.
"I don't think what you've seen is any way representative of the way in which Barclays does business, and I'm sure our millions of customers would tell you exactly the same thing."
Whistleblower - Banks will be broadcast on Wednesday 21 March at 2100GMT on BBC One.