Can't get Altech Netstar OFF MY BACK!!!!

I have been trying, for over a year now, to get ALTECH NETSTAR OFF MY BACK, but it seems impossible. I have tried to cancel my contract, but they are still chasing for payment, which they should be claiming for. It all started when they debited my account R800 ( 3x the normal premium)- when I enquired, they advised me they had not debited my account for 3 months, hence they raised a triple debit. They couldn't even give me a valid reason why they had stopped . I immediately asked for their services to be cancelled. I have had endless nightmares dealing with Altech, I don't get feedback from the so called managers I have escalated to. They have the odesity to hand my account over to Creditwox, when they can't even account for their error. Bottom line is, I don't want anything to do with Altech Netstar, I just want them to remove me completely from their system. I need them to investigate the so called outstanding amount that they say I owe, because they are even charging me for the months that I asked to be terminated. I will NOT have a bad credit record because of their incompetency. I have since sold my car, but I am still involved in a stupid endless war with NETSTAR.