MTN incapable of doing something simple

About 4 months ago we did a change of ownership on my ex wife cellphone contract

as off today 2020/12/10 the phone has been removed from my name but I still end up paying for her phone. after countless phone calls and countless hours spent on hold nothing has happened. I still end up paying for a phone that is not on my name. And I can do nothing about it!!! reverse the debit order and I get blocked! phone in and I get placed on hold for hours.!!!