Telkom and sell direct failed me

I have called Telkom several times and Sell direct as well requesting them to stop billing me and all the time I was informed that a call is logged and the billing will stop with their accounts department but I'm still billed for device I don't have and service never received from Telkom and Sell direct. They refuse with reference no .Never never will I do business with *********** service provider or their so called brokers.