Bad Service Nedbank

I had a American Express credit card through Nedbank, my account was paid in full 01/08/2018. I send a request to close my account and cancel my card. After a while the query showed resolved, but my account was still open and there showed an outstanding amount. I sent another request to cancel my card and close my account. The querry was pending for a while, when I checked this morning, the querry shows resolved, account still open and the outstanding amount increase. How is it possible to charge fees if a request was sent to close the account, the account is paid in full and there was no further transactions on the account????