MTN has pathetic service and are ******.

My contract with MTN ended, end April 2020, I called them on the 12 April and requested cancellation, they advised that it would be 30 days notice and that I would need to pay R 309 the following month. I agreed, and then paid. May 2020 my other line was suspended due to non-payment, on the line that was supposed to be closed, I called them they advised that it fell into the new cycle, so I need to pay again. Then in June again I called and the line wasn't cancelled as there was still "an amount owing", I called to unlock my line and they advised that I need to pay the amount. I advised that this line was suppose to be closed but the continuously charge so it never gets cancelled. Again today the line gets suspended, I have to keep wasting time to call this useless service provider. I need this line cancelled immediately. How can you keep charging for something that has ended. Bunch of ******.