Can't say too much (name the bank), but am about 18 days from similar action myself, and if it does go this way, I'll make sure the footage appears on ARRSE first. Will also tip off various journalists and interested axe grinders!
And for anyone who's been drilled and used as a cash cow by their clearing bank, take ten minutes to look at the following thread and associated linked web site:
I got pi55ed off with charges on my Credit Card that were excessive to say the least. Call centre wouldn't play so I sent a cheque for the full balance to the Group director stating that he could either close the account or refund the charges. Funnily enough, a very polite young lady phoned up a couple of days later explaining what a terrible mistake it had all been and of course they'd be delighted to credit my account.
Only snag is you need the readies to be able to put them on the spot.
I have found that the easiest way to get a response is to E Mail the CEO or MD when you have an issue. Worked for me with British Airways all I had to do was ascertain his name and add @ba.com. Now of course the fact is that he does not receive these messages which go to a team of minions who sort these issues out. worked for me with them and one of the mobile phone operators.