Autopage Breaches contractact and hounds client

During May 2014 Autopage Headquarters decided to call me as a client of their branch in Northgate to inform me that they were going to upgrade my Unlimited Wifi account, I asked how they can upgrade an unlimited account for which I never complained and I was told the coming change was assessed to be beneficial to me. I was paying R300/month and in about 2 days after I received the call I discovered that I was downgraded to 2GB from an Unlimited Wife account costing me +-R300 a month. The following month, the bill owed by me was no longer +-R300 but R6,000. I complained, I wrote letters, went to the Northgate Branch and complained, they put through a complaint on my behalf and it was finally agreed that they would credit my account. That apparently, did not happen and a Ms Samantha Chetty has now decided to hand my account over to VVM Attorneys who are threatening me on the phone not willing to tell me about what they know about the case. I also have an e-mail from Ms Samantha Chetty who admits to my predicament but rather than writing off the account wants me to pay a portion of it, without giving reasons as to why I should when I know I am innocent.