MTN unauthorized contract change

My contract was changed **********ly in May, contacted MTN, they kept on providing call refs, and closing the call without resolution. Went on Twitter, told them my issue again, provided all the call refs, was told that my call is logged with system support, turn around time 3 working days. After 3 working days, no response, followed up again, it's now 7-10 working days. Still no response. These guys are just lip service that does not know what they are doing. I'm sitting without the data I signed the contract for.