Unauthorised debit order

MTN is debitting money from my account without my consent and I reported the matter with Mtn and I was asked to submit the affidavit and copy of my Id to the consultant of which I did but till today I haven't had any correspondence from Mtn. Its almost 2mnths now . I was told that someone opened cellphone contracts using my name at Mtn in different places, and my question is how can someone open 7 cellphone contracts? Please assist me