BEING OVERCHARGED FOR DATA FOR OVER 3 MONTHS

It has now been 3 months since the constant overcharging on my MTN account started. The first month MTN TOOK the money out of my account even though they admitted it was their mistake. Money I still haven't been refunded after countless calls to MTN (I refer to REF NUMBER: ***) MTN never took the opportunity to correct the biling and the next month it went up to a whooping R3900 from the standard R549 that I am suppose to pay (as per my contract agreement which clearly proofs that MTN is in breech). I refused and made many attempts to reach and correct this mistake made by MTN. Again I was given Ref no after ref no after promise after promise which turned into lies that someone would supposedly contact me from the billing department to correct MTN's mistake. Then the STRIKE HAPPENED!!! and the valued customers suffered in the process. Month 3 arrived and again I was being overcharge for data when my data was switched off the prevent data charges....MAGIC!!! no MTN to complain to because they are striking but amazingly someone was always updating FACEBOOK about their amazing specials.....seriously? I have requested to cancel my contracts & still no MTN!!!!!!