Worst Service Ever

I have been trying to cancel my Phone line on my ADSL since 30 August 2017. And Tekom still just sends me Bills every month that increase. I formally gave notice of cancellation according to the process that Telkom told me. But this seems to have just gone into a black hole. I was initially assisted by Faith but am getting no joy from Faith or any other person. Please help me to cancel my account and refund me the additional months that you billed me. I gave notice on the 30 August 2017 already.