I think I got lucky. This was a good 30 years ago, so my memory is a bit hazy, but I think what happened was that they deactivated my account, which incurred the charge. Since I didn't technically have an account any more, they couldn't do anything. I suspect that they weren't supposed to actually deactivate the account completely and screwed up. Back then banking systems were a lot less computerised so I think there were probably lots of errors.