service cancellation and incorrect billing

We had our Internet cancelled in April 2015. Telkom removed the dsl line to our house but keeps on billing us for home uncapped. We have been in to the branch 3 times and were promised that a correction would be processed. No correction was done and we are still being billed for a home uncapped charge even though we don't have a dsl line. My mom even asked to have the telephone line cancelled a month ago and the line is still on. The charges on the statements are accumulating and they are not actioning anything. The lady that I spoke to telephonically reads me the notes on the system, which are correct, however she refuses to action them. please help us. I don't think telkom cares about how bad their service and system is.