Wrong Billing

I received a modem and sim card from cell c but before I took a contract with them I was told that my subscription fee will be R109 per month with 2Gigs of data's every month. By the end of May 2015 I was surprised to see my account billed R1800 for the contract. I thought it was mistake that will rectified by them, I disputed the transaction from the bank. The sim card barring was activated by cell c since the bill for the month was not paid. By the end of June Cell c attempted to debit R3,659.85 from my account. I called Cell c dispute this unauthorised transaction and I was told it will be investigated within 48 (That was beginning of July). Last night again, Cell c attempted to debit R3785.34 from my account. I called Cell c more than 3 x times as per ***,*** however up-to-date no one informed me about the progress of their investigation. I asked myself one question which is \Cell c is bragging about buying other customers contracts from the current network operators so how in heaven are they going to get there if one simple incident is taking them almost a year to resolve? I have been with this network for more than 5 years but after this incident I doubt"