Mtn complaint

I am a very unhappy customer with mtn service. I had a contract for 36 moths and when the contract had ended mtn still wanted to charge me a great amount for data. When I went to quiry this they were rude and eventually hang up the phone in my ear. I can no longer use my older number and its been two months now. I went to the waterfall brach in rustenburg and could not get assistance. They finally advised me to contact hello peter as they were not able to help me on the premises said my problem needed me to call ecenyre