MTN - Terrible Service/no Feedback

My wife was contacted by MTN's debt collectors for an outstanding MTN account of R13 522 This was a huge surprise as she never had any contract with MTN. After several attempts to get any info on this MTN contract, we are still just were we started. A Ticket number was eventually received on 6 July 2018 - Ticket number ********** ********** 28 This was the last feedback we've got from the service desk, MTN phoned her in last week, but this was not to give feedback on this query, they wanted to sell a new contract to her ! This MTN account is now listed on her ITC, but MTN never came back to her. No proof can be given of any contract documents signed. No number with MTN can be given. There was never any debit order from MTN She is now blocked from any credit applications due to the above!