Data Spike

I always received bills of max of R800 (with subscription fees) and now for the last 2 months, I am constantly struggling as they soft block my phone almost every week! Reason being that I exceeded my data bundle, I always received a text message to notify me when this happened and when I app**** for my contract I specifically asked them to ALWAYS do this as I know how ridiculously expensive out of data bundle rates are and now I'm not receiving them anymore and my data cost are running up my bill. I honestly don't have a idea how I was able to use 2 gig up to now, it has never ever happened before and I don't think it is possible. Problems all started when I was told that I was put over to a new system, but that is not my problem. Why should I be given less service and more expensive monthly bills!!! Last week one agent told me my bill is R1600 and this week the other told me its R800 (without subscription fees), i am not even sure whats happening. I do know if it continues in this way I will take up Cell C's offer to buy out my contract as I am not going through this every month. I had to be at a meeting a hour ago, but had to cancel as I can not be on the road without a phone!