Bad customer service - ***** Account

Somebody open a ********** account using my Identity. I went to Boulders Mall to report this and I was assisted by a lady called Lucretia. She said I must go to police station to write a affidavit to confirm that I don't own any device or account with MTN. I did that. She loaded the query on the system, and she gave me a ref no *** and promised that it will be sorted in the next week. After following her up number of times I never got any assistance. Instead she told me to call MTN summer mobile in order to confirm if I didn't have a contract with MTN. But she had all the details why she is not helping me to close this issue. I have no idea. I am still harassed by their lawyers wanting R4 300 that I am owing MTN.