Telkom Still Charging Me For a Service I Cancelled 10 Months ago!

In the beginning of July of 2018 I contacted Telkom to advice them that I am moving house. They said I could move my line over to my new residence. When the technician came to my new house he said he wouldn't be able to offer me the same line I was on as our new house was to far away from the exchange. So I called Telkom and said lets rather cancel the line completely.

In September I received a bill from Telkom for the service at my old house. I contacted them again to say why am I receiving a bill when I have cancelled my line? Then October, November, December etc etc etc until now (May 2019 - 10 months later) I am still receiving a bill. Every time I call in the agent says they will escalate it and I should get feedback in 7-10 days. Now I'm getting letters of demand and threats of legal action for a service I am no longer using and cancelled almost a year ago. This is causing unnecessary anxiety and is bordering on harassment. If this does not get resolved in the next two weeks I will go to the small claims court and lodge a claim against Telkom for wasting my time. This is so unnecessary and really should have been resolved months ago.