Unresolved query

I have been taken from one point to another without any proper response. I am not happy with the service I've been getting from MTN. My account was double debited, in June and August. I also made a cash payment in May, till today that payment hasn't been allocated to my account. I have called their customer care line numerous times and they all tell me different stories. I called the head office, even today they haven't resolved my query. I've visited 3 MTN stores but still nothing. I was advised that I must send an email to the complaints department, I did that. It's been 10 days now and still I haven't received any feedback. It's month end already and MTN will be expecting their payment. It's totally unfair that we always pay as per advised, the payment gets credited and not allocated. Can someone from MTN help me to resolve my query. The credited amount is a lot to just loose it just like that.

Unhappy client