MTN Sucks

I was over charged end of OCT I called in on the 3rd NOV to query about what I was charged for. They than explained to me and I told them that I was not told about those fees on a new contract did a investigation which approximately wud take 5 to 7 working days and It was in my favor that I was not told about it so they said the money due to me would be paid back.I have been calling to follow up since than up until today 8 Dec. So it was easy to take my money but now it's taking them over a month to pay my money back and it's not a 100 or 200 Rand it's R1582. 00