Cell C is ruining my credit record

I'm writing a 3rd review about cell C for the 3rd time without getting anywhere. And I know no one from Cell C will come back to me about this unless if they are selling me something. Early last month I've canceled my contract and to my surprise my account was handed over to the debt collectors. Mind you this is one ruining my Credit record. The amount that they say I am owing, I've sent a proof of payment in August which I still have an email I sent and I never received feedback about it which I guess it was never attended to. Now this thing is getting to my nerve because I explained to VVM debt collectors that I don't owe cell C and they requested me to send them confirmation that my contract was canceled which I did but now they want me to send affidavit stating the dispute, my six signatures and ID copy. Like really now why do I have to go for so much trouble for a contract that is canceled. Like first of all how did the contract get canceled if I'm still owing then and why must I send all those things for investigation to run?. I've stated this before and I will state it again that Cell C is a Circus full of *********** clowns, coz obviously the lady I sent my proof of Payment to didn't do anything with it. I don't care if Cell C responds to this or not but believe me I will take this too far