If you are getting calls from the a*holes just block their calls. They are not going to stop if you tell them they have the wrong number, send them them a certified letter, report them to do not call list or report them to your attorney general.
If you have a home phone all you need to do is get a phone with caller id block. Uniden and Panasonic make them now. The uniden I have does not even ring once, just blocks their calls. If they call on your cell and you do not have caller id block, just save them as a contact and set their ringtone to no ring.