Mtn sucks

All I want is to cancel my mtn contract and go to prepaid. They say that you must give 1 month notice so my contract ended in November 2022 so I foned in October to cancel my contract and go to prepaid. Allmost every day I'm calling mtn up to this date and no joy, I'm paying a lot of money for minutes and data which they are still billing me. When I get through to mtn call center, the person will transfer me to another person then the call will get cut then I must call again.