contract cancellation

I had a contract with MTN which expired 2022/10/27, I called to close/ cancel the contract but it was not closed as per my request. MTN blocked my Sim card that I owe them after reversing my money due to unauthorized debit. i went to pay R360 on the store in Greenstone Jhb to avoid black listing, the agent call the service desk to close my account, the closed my account only Feb, then this month again MTN debited my account. I do not understand because i even destroyed the sim card the way i was so angry. why are you keep on debit my account without any contract in place? what one must do to do away with you ?

MTN needs to hold their agents responsible for this things, how does the account reactive itself ?