Impossible to close account/harassment for "outstanding amount"

Battling to close account since Oct 2021. Have not been using the account for more than 2 years. Keep on paying the outstanding R50 or R100. Constant harassment that my account t is in arrears. Numerous emails, phone calls, etc. Once again yesterday "your account is in arrears" and they refuse to close it. So...they keep the account active so you need to pay everything to close it and then they don't close it?