If only I could sue Telkom

After about 2 years of trying to sort out my issues with Telkom for a device they claim I have taken when I actually returned it back to the store 3 days after purchase since it didn't meet my requirements. I am now sitting with arrears amounting to +4k. It seems they cleared the 17k they claimed I owed and nor the arrears are down to +4k. I don't know who can help with this but I do not owe them anything. They need to go back to the beginning of when I made a device purchase. I had a Sim only month to month contract and all was conducted fine until they cancelled, or should I say blocked it too, when the claimed I owed them. This has never been in use since. So, in effect, they owe me for all the judgements and blacklisting and bad credit status they have put me through. My credit rating is tarnished because of them.

Regards Sema