******* way of making money

The contract I had with MTN SA ended at the end of August 2024 and as per their advice, I could only cancel ot from 1 August 2024, which I did and was told my last invoice will be debited on 15 Sep 2024 which I understood but then all of a sudden they send me a bill on 19 Sep 2024 which is payable on 25 Oct 2024. I called the billing department and was told they could see on their system that the contract was canceled on 2 August however it's still open hence they billed be, can you believe that? I was then transferred to cancellation and the lady I spoke to told me that she doesn't know what it was not closed, could be a system error. When I asked her to then reverse the 1gb they loaded without my concern she said it's not possible and I will have to pay for it. I told her straight that no one sells me their product by force, I did not ask for the data and as such, I will not pay for it and should they debit my account, I will take whoever was supposed to close whatever to task, and will keep on reversing such debit order until they stop with this ****gish behavior.