I told one, back when we first moved to Indiana, that whoever-in-hell-it-was-they-wanted was uglier'n a mile of homemade mud fence and we shot him out of pity. There was a long pause and then "Ah, okay, um...." and a hangup.

Recently we got some over a disputed bill with the local hospital. My wife just asks if the caller has the authority to negotiate payment and that shuts 'em right up.