I've been know to do this with telemarketers. Back when this was a problem, I figured that if they called me when I didn't want to be called, then it was OK to tell them ANYTHING
One night, a friend was over, and one of the "back then" TV "ministers" was in "full swing" so I called them up and gave them a big sob story a bout "how I'd donated lots of money to them in the past," "but now I need some BACK." Cheeerieeesst you should have HEARD all the backpedaling and excuses!!!! It was, franky, amazing. My friend was laughing so hard I had difficulty holding the conversation together.
