Stop Harassing me

I received numerous SMS's, telephone calls and emails from the Call Centre at Shapiro Shaik Defries and Associates (SSDA) to say that I have an MTN account in arrears in excess of R24 000.00. I repeatedly informed them that I have never had an MTN contract, nor pay-as-you-go number or account with MTN in my life. When I asked them to send me a statement, the statement contained no initials and an address in Johannesburg somewhere. I advised them then that I have never lived in Johannesburg, nor in a street with the name as per the statement provided by them. I have been to the local MTN branch and they verified that a search on the account number provided by SSDA, as well as a search on my ID number yielded no results - nothing exists. They seem to ignore what I say and continue sending me emails and calling me. They need to stop harassing me.