HIgh BILLS, NO FEEDBACK FROM MTN

I usually get bills of about R3000 - 4000 to my mobile phone because I roam. My bill for December came at 20 000. I tried to call the MTN customer care line for two weeks without success because it either rang nonstop, or when someone picked up after 45 minutes of waiting, we got cut off anyway. Finally, I went to the agency in Northgate and queried the bill: Ref Req***. I called 808 again and no response. I was sent to 14th avenue, and they asked me to come the following MOnday and meet Billing. I went there Monday 23 Feb and met Ntokozo, who lodged a query in front of me into the bill, and promised that within 48 hours, I will get a response from MTN on my email. HE registered me for itemised billing, and we checked the bill together - it indicated that most of the 20 000 came from charges on one day in Nigeria, which is very strange and unlikely.Till date. there is no email, no response from MTN, the customer care line is still not responding. Ntokozo said he had put a mail in so that my line could be unsuspended pending the query. NO response, and my line is rather been fully suspended now. There is no transparency, no feedback and I feel like MTN is taking me for a ride