Unfair business practices

I have had a internet service with Telkom since last year October. It went well for couple of months and then August this year it was dead. I ran speed tests and the only speed I got was 3 down and 044 up. I then mediately reported the matter. Month later the problem was not resolved. People this is after numerous emails and phone calls. I decided to put a stop to the debit order! They then quickly phoned funny enough about payment for services I did not receive. I told them I will keep reversing payments until services is returned but out of goodwill they can extend my contract by the amount of months they do not receive payment for non service delivery. Now we are in November the matter is still not resolved and they still demand payment with penalties involved. This is unfair business practice.