Incessant Calls - Not My Account

I've been getting calls and sms's, almost daily, and sometimes more than once a day, for someone else's issues. Your call center staff keep asking for the guy and I have repeatedly told them that he no longer works for our company (FOR OVER A YEAR) and I have no idea how to get hold of him. The number they call is a company number, which I have also repeatedly told them, and he no longer has access to it. Also, they have told me many times that they have deleted the number.....WHY am I still getting the calls then? Are your records not updated? It shouldn't be my problem that you can't find the guy.<br> <br> I've put his account number in (which I received as an sms for him) for you to see his details.