MTN IGNITION (NEW CONTRACT)

I called MTN on 26th of March and asked to change a pre paid number to a contract, i provided the number that suppose to be a contract number and all necessary documents by email, a lady from MTN ignition was in touch with me couple of times and finally MTN approved me for a contract. after couple of days they sent me a contract and i noticed the number they swapped to contract and loaded data is not correct and isn't the number i requested. i called them on 10th of April and report this, they supp**** a reference and asked to wait for 48 hours. after couple of days i received a invoice mentioned that incorrect number again for debit order and since that date i called 15 times to follow up the matter and no result yet. the lady helped me on first day and manage the contract also doesn't answer my emails. Unbelievable act from MTN and no one doesn't know who can fix this mistake. data loaded to other number and i have to pay the invoice!!!???