We have a Panasonic phone that we can program to block up to 250 phone numbers. It has been a God-send. Whenever one of those calls come through, I just program it to be blocked - because you know they won't take one "no" for an answer. We can also block all calls from "private", "out of area", or "unavailable".

When one of those numbers call, we hear one ring - and then nothing. The calling party just gets disconnected.