Hi.
First of all ring your bank and explain the problem. Make sure you make a note of what is said and who you speak to. This may be usefull later on. If you then get what you want fine. If not make a writen "Subject data access request", paying the fee of £10 (fixed by law). The application is under the Data Protection legislation and the Bank are obliged to send you copies of all the information they hold on you including details of default charges levied.
The information has to be provided in readable format and there is a time limit for them to comply. I think it is 42 days from reciept of the request. If I am wrong about the timetable no doubt someone will correct me.
Have fun and good luck
problems