MTN is ******** their customers

I took a standard contract with in MTN March 2017. In August 2017 i start nticing that i was being bil**** twice by MTN through a false account that has been created in my existing account using a different number. When i called MTN i was told there is another number operating under my name and its was opened in June 2017. I told them the number is not mine and I have no knowledge of it. I was told by the person that was assisting me to send through an affidavit and certified ID copy so they can stop the account and do an investigation and the money debited from my account will be returned once investigation has been done. I have contacted MTN a number of times and no investigation has been done instead i am being shifted from one caller to another and they keep making empty promises and yet my account is still being charged for a contract i did not sign for. I want nothing to do with MTN anymore.