6 + months ..still waiting to fix my problem!

I agreed via telesales to a 24 month 2 gig Data @R99 pm contract with Cell C through a consultant from FNB. For 18 months my ac was R99 as per contract. Suddenly I received a R500+ account and the following month a R1000+ account! After MANY phone calls they said \I went over my allocated data". My Question to them was: HOW WAS THAT POSSIBLE? They dont know..Question 2 to them was: Why did the consultant NOT warn me that I could go over the contract allocated 2 gigs? <br> They just dont let me listen to this tape! I receive calls from them acknowledging my emails and then nothing!<br> Last year they said they are waiting for First National Bank for the recording"