Hassle with cancellation of contract

My mtn number is ***,i have been trying to cancel my contract with MTN since the 3rd of july 2020 and have been **** to by mtn ever since that day .every day they promise to cancel but they dont .there is a reason why I dont wish to upgrade or continue with the contract but they still want to take my money against my will .I dont recommend anyone to do business with mtn as they are full of **** and nonsense. They are doing this deliberately so that they can debit money again this month this dogs