Contract half cancelled

MTN SP: Cancelled a contract that I pay for but is in my fathers name. My father did all the neccessary checks to process the cancellation. I still receive a bill for R0.00 every month. Multiple mails to your retentions department has not resulted in any luck as they cant see the notes on the system. I used to work for MTN 10 years agao and it was a headache to cancel contracts then and its still a headache. I tell you that MTN is only interested in getting a client ton "sign on the dotted line". I wouldn't sign up with them even if they offered to pay me. Useless.