Standard bank not closing my paid up account so they can keep charging me fees

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 sent multiple emails to Justin Pillay and Sunday Nakana but I'm being ignored. I'm very disappointed not for the first time with Standard bank