good luck - I've had exactly the same issue with Lloyds and they've been f*cking bastards and have lied to me about the whole issue repeatedly...I'm beyond fed up with them and have ended up closing my account as they took around £200 off me in OD fees.
Some banks will relent and give you back the money, but Lloyds isn't one of them. Best bet is to visit the MoneySavingExpert website...in their forums there's a section on reclaiming unfair bank charges and they'll have copies of the forms you'll need, which you can print off, fill in and send off. Don't expect miracles though. The courts have already found in the public's favor, essentially, but the banks are appealing to the House of Lords, despite previous court rulings saying they can't (looong story). Anyhow, likelyhood is this will be resolved in public's favor and banks will have to admit their charges are unfair, but at best you'll be in a queue behind 1,000's of other people waiting for payouts and at worst the government will say that the banks wont have to pay back the charges due to the current economic climate (as it could cripple the banks).
So yeah, fun stuff :P