No feedback or help from vodacom

I cancelled my contract with them in December last year. Sended them all the docs the wanted got no response. They then continued billing me and I reversed the debit order. Spoke to numerous people and resend all the docs. I can not tell you to how many people I have spoken to at vodacom and no one gets back to you. I have proof of every mail sent I even went to a vodacom shop and they sent emails to HO but still no reply. Vodacom have blacklisted me and gave me a bad ITC rating which is absolutely absurd considering that this whole issue is there problem and fault. This is the reason I left vodacom in the first place. They are absolutely the worst service provider in the world. I want my ITC rating updated and everything sorted out because I will be exploiting all avenues to express my disappointment and will take legal action because of my ITC rating.