next time they call do as I did and agree with everything and when they show up just give them the bird and say how do you like wasting your time [***].
I agree, it's getting worse every day. I thought of recording a message that says if the caller will not leave a message, the number will be reported to FCC. However you're right, the FCC threat won't phase them. This is getting more than annoying - something HAS to be done, but what?