Trying to get my credit card account closed permanently

On the 03 January I went into a Nedbank to have my credit card closed. I used their phone to contact the call center. I requested that the card be closed with immediate effect. The account is still open. 2 days after I requested the account be closed Nedbank added fees of over a R1000. When I requested that the card be closed it was in a positive balance and now is in a negative balance. Is this a way to keep the account open and add fees? I am going to close my cheque account due to this.