I know I'm new, but thought I'd stick my head above the parapit again! I'm glad to read the particulars of claim you have on site mentions the UTCC, I usually refer to them as unfair terms as defined in section 5, schedule 2(e) UTCC regulation 1999 - winds them up more when YOU get technical
I wonder if you might consider add an 'unjust enrichment' claim to the particulars as well? As the banks owed a duty of care to the consumer in the form of a fiduciary duty not to gain extra profit by way of 'fiduciary improprietry'. Now, if the court holds that the charges are unlawful, anythign that flows from such charges are fruits of the same poisenous tree. So, you go overdrawn £100, the banks slap on a £30 charge, they charge debit interest on the whole amount, there by a profit by wrong doing or 'unjust enrichment'. Therefore a claimant can claim restitutionary damages - it is hard to work it out exactly, but I usually add on£10 per hundred. If they want to argue the toss its going to cost them alot more than £10 per hundred to get a forensic accountant to calculate how much the made from unjust enrichment!