Bad Record for not paying fees on closed account

Received an sms from an Attorney that I am now handed over for not paying my credit card fees.<br> I phoned the Attorneys and asked what credit card seeing as I closed my account more than 2 years ago.<br> The lady explained to me that I am now listed as a bad and slow payer and that this will affect my Credit Record, I first need to pay X amount in order for them to reinstate my clean record. My question however is if I instructed someone to close my account and this was not done, why am I at fault for not paying something that does not exist, I cut up my credit card the day I closed the account. I would like someone to explain to me how this works?