Harastment for not even my own account

I receive calls almost every day from ********** 663. My cell number is ********** 998 I am getting very frustrated with you guys because I tell you every time that I do not know this person that you are looking for and to remove my number off you system. you guys just say sorry and phones again. this needs to end now as you are harassing me for someone else account. I never seen such poor service and I do know what I am talking about as I was for 11 years a debt collector myself for one of the best companies in South Africa and you yourself work on some of their accounts and this is really pathetic