rong billing

I took my contract in may could not use and set my limits for two months kept on going to the store to sort my contract out the consultant kept on sending me back as she could not do anything as MTN was on strike so in July wen when the strike was finished I got an sms that services have been resumed and I called the call center to for my Sim to work as it kept on telling me that my Sim card was barred as I called the call center they told me that for July I will be billed R200 and some cents from my contract and I asked for my limits to be set then I called two days later to make sure that the consultant did the right things then the consultant advised and confirmed that in august I will be paying R150 and now they took more and I am being told that I was charged an extra 39 rands for internet that I did not use as I called in the same time to set my limits when they were back from strike what's the 39 for when I could not use the fone and the Sim,I am not willing to pay so much I was told my contract is R150 not R180 or whatever it is. I want my money back I will not pay for what I did not agree on.