Same as all of the above. These can be really fun to call back on. The game is to try to get the scammer to believe that YOU believe him and want to pay him money, etc. If you're creative you can tie him up for quite some time just feeding him bogus card numbers, unusual requests like you have an urgent need for the bathroom and if he doesn't mind you'll just have to take the phone with you, etc, etc, etc. The more you think, the funnier it gets. Have fun with it!