Standard Bank Refusing to Close off my paid off account and listing me as a bad payer because I won't pay the admin fees for a paid off account.

I app**** for a personal loan with Standard bank in 2017 which was approved. I have been paying extra on this account to ensure I finish paying the loan early. I finished paying the loan late last year around October. However, Standard bank kept the account open so they can keep charging me monthly fees and keep debiting my account although the loan amount is fully paid. I received a paid up latter from standard bank (Justin Pillay) in November which assured me that my account would be close off as they is no outstanding amount. In fact, there was positive balance on my account but the account was not closed off by Standard bank. I think this was strategy to continue charging me their service fees and use up the positive balance until they start debiting me again. I have now been listed as a bad payer with standard bank due to refusing to pay for negative balance caused by Standard bank failing to close the account. I recently got refused to get credit because of this account but Standard bank cannot close this account and clear my name. Its going to be 10 months now since I finished the loan but still the account is not close. have sent multiple emails to Busie Moilwe but still not close. I have complained, called, email did everything possible on my side but still no luck. I do not know how Standard bank get clients if they can't do the basics. I will never again consider this terrible bank in future.