Still Awaiting feedback from MTN's ***** division

Just over a month ago, on a Sunday afternoon, I received an SMS from MTN stating that my number had been ported to them. (I have a pre-paid service with Telkom). I did not request my number to be ported to MTN. I tried in vain to speak to someone at MTN about this on the Sunday, but I was advised that I would have to speak to the porting department on Monday as they are closed on a Sunday. I did also speak to Telkom on the Sunday, who suggested that I send through a port request to them, to have the number ported back to Telkom. This I did via a SMS. The number was duly ported back to Telkom and has been working fine ever since. I did send a query via an e-mail to MTN's ***** department and asked them to investigate as to why my number was ported to them without my consent. I received an e-mail back from them stating that they would investigate and revert back to me within three working days. That was a month ago now. I have since following up with them again, but to no avail. I originally suspected that it could be someone wanting to perform some ********** activity, and would like to know what the reason was. Just wanting a response from them.