MTN *****s money from their customers

I have a very long relationship with MTN, since 1999 but in 2015 I just got accounts high above my normal spendings. I lodged complaints at Somerset Mall and Tygervalley branches, got reference numbers, but no answer. I have a top up option and every month there are minutes and date carried over to the next month. Nobody wants to explain why I suddenly get accounts of between R150 and R300 more than usual. It seems that I am not the only one they ***** from. Is it to pay their fine in Nigeria? Can I go to the police on the Consumers act, because you go to prison if you ***** from others.