No Contract, Being handed over

Received phone call from Mtn telemarking and was offered a contract but told them i was not interested. Courier came to deliver the phone and i refused to take it as i had told Mtn that i was not interested! Couple of months later i found out that the Mtn account was on my name and it had been listed on ITC, went into Mtn store in Canal Walk with an affidavit stating that I never had an Mtn contract! Today I have received a call from Mtn collection attorneys telling me that my account has been handed over. My account has been debited on two occasions for an account that I do not have and i have had the debit orders returned and had to pay bank charges! Does Mtn not check up on these things as according to Mtn store in Canal Walk the numbers/account is inactive which there is two numbers listed on my name.