MTN is ruining people's credit scores.

I'm very disappointed with MTN ***** department. I had a problem with an unknown person who used my details to open an acc at MTN of a cellphone contract. I discovered this when I saw a debit orders that I didn't recognize. This person even opened an acc at Telkom. I then reported to MTN and Telkom and provided the requested necessary details with documents to both companies. Telkom was prompt to attend to the problem and canceled the account. However MTN continued to debit and even now I'm blocked from opening any acc in my name because MTN has listed me as someone who doesn't pay accounts. MTN won't cancel the *****ulent account, I've been calling and submitting documents over and over. They even see it on the system it's a *****ulent acc but still won't clear my name. This is tarnishing my credit score. Please assist. Thanks