No Feedback for Incorrect Contract Package

I renewed my Cell C contract via telephone. I spend almost an hour to get a deal to suit me which included a data package. To my surprise this was not done according to our telephonic agreement and I just got a bill for about R700 more than I usually pay per month which is directly linked to data usage. I have logged a call on 29 November but have had no feedback and phoned them twice to which I was told that the call is still open but nobody has started working on it. I want the phone recording to prove that they were in the wrong and they need to rectify the contract and carry the data cost.