Did you move house, or change bank account? Could someone have been taking your post? Is there more than one person involved?
They have their proceedures and its all done according certain rules and guidelines. This sounds very weird. Try to give us more information.
If you owed the bank charge, then it is surely payable. Charges can be incurred and you will be liable but it does sound incredible that all this has been going on and you didn't know a thing? Have you asked them why they haven't contacted you in all these years?