vodacom/vvm

I have been struggling with vodacom for months now. We arranged for payments every month for the areas amount. I paid a certain amount and requested a statement where vodacom sent a settlement letter. For me this meant no more payments. After a few months I got contact by vvm that I was handed over to them and the amount is more than what was owed at the beginning. After a lot of emails being sent vodacom said that the settlement letter was wrongfully sent by their people and I understand that. I am still waiting for my statement breakdown today. I said that I will only negotiate with vodacom on the first amount taken the amount that I have already paid and not vvm as the fault wasnt on my part.