Unhappy with MTN, happy with one call centre lady out of a 100

My phone number was converted to contract and then to prepaid again in a space of a week (story for another day). When I got back to prepaid, I noticed my airtime was being used for internet even though I had data loaded. I phoned the call centre, The first guy was very helpful in the sense that he managed to credit my airtime and told me he had escalated my query to a different department and they would come back to me. One month later, my query is still open. I have lost count of the number of times I have called the call centre and my query doesn't get resolved, not to mention the inconvenience of loading airtime and when yo want to make a call, you hear that "you have insufficient airtime" message.

Finally, yesterday, I called and I spoke to a lady by the name of Dumela. She was able to assist me and explained where the root of the problem was as well as ask her team leader to credit the airtime that was used for Data in this whole month.