********** MTN Upgrade using my identity - MTN not responding matter pending from 2016

In 2016 in the month of September I had 3 months left of my contract with MTN paying an amount of R275 it was for a Samsung Tablet. End of September I was debited R600, when I queried the debit via customer care line I was told there was an upgrade in using my identity. Immediately I advised that I had not upgraded with MTN proceeded to immediately reverse the debit and pay what legally I owed to MTN. During the months of October, November and December I sent numerous emails and made numerous telephone calls to MTN to clear this matter up. eventually after numerous escalations and reference numbers quoted, I was advised to go to the police station for an affidavit. which I do and submitted to MTN. end of January 2017 the debit stopped. in May 2017 I was contact by a law firm Norlam acting on behalf of MTN regarding an amount I owed. I then contacted the customer care centre and they confirmed that this matter had been settled in January and that I should not worried. Emails from Norlam have not stopped and they are now calling be non-stop. when I made contact again with MTN ********** and Norlam on the 01 November 2017, MTN has still not rep****. I had my husband's phone and mine on contract, and internet ****le and a tablet, all of which were paid for in full and I did not miss not one debit order. Can someone from MTN please assist to resolve this...