Supersonic - very poor service

I have never experienced worse service from an ISP ever. I moved houses within Cedar Lakes estate Fourways and when the move happened, more than four months ago, Supersonic decided to make me pay for two lines. I have tried every month to get this credited. I have now paid more than R4000 more than I should have and once again calling their call center gets you no where. You cant escalate to a manager, your calls get unanswered, you get promises that it will be sorted out. Yesterday I called again as I have yet again been billed the additional line, I was promised that I will get a call back and of course nothing again!. I cant cancel my subscription as they have the monopoly on the fiber. totally unacceptable and wont go away.