At that point I set the phone down, line open, and go back to watching "Green Acres."
It goes down hill from there in civillity.
I understand that people have to make a living somehow, and not everyone is cut out for more honorable and socially acceptable work like mucking out hog pens, and will give the caller a chance to cease and desist gracefully.
Some just keep going, and I will (if I am in the mood) play them. When they ask for a credit card number, I respond like Hashimoto in the old Cheech and Chong bit. (unprintable response on this forum)...and continue with "YOU called me and you expect ME to just give you a credit card number?? Are you nuts? I don't know who you are! You could be anyone!") And then hang up.
Maybe they will learn not to waste their time with people who say "no".