OVER BILLED BEYOND CREDIT LIMIT

I am disgusted by MTN's service and after this call has been resolved I will never have a contract with them again. Firstly I cannot speak to anyone anymore because apparently their services have been disrupted and the call centre has closed down. Secondly I have a contract with a credit limit of 836 and all of a sudden I get a May invoice close to R3000. I try their so called self-help service and no help, there is no way even if I didn't have the credit limit, that I would make calls or use data worth 3000 rand when I pay additional data in any case to be on the safe side. I am disgusted by their service as I currently cannot reach anyone to sort this out. The debit order goes off on the 25 and I will have to reverse this at an EXTRA cost to me until it is sorted. Once this contract expires in August, be certain I will not renew it or do any kind of business with MTN again!! Absolutely disgusting!