It is fun to waste their time a little. I like the telemarketing calls. Ask a bunch of questions to get all the details then cut them off. One of the best features of Bluetooth in my truck. I talked to one for my entire 30 minute drive home. Gave him all false information to key into his system.
Him: Sir this address is coming up as in invalid.
Me: I know, because its fake... I am just deliberately wasting your time to keep you from harassing someone else.
Him: excuse me....?
Me: yeah that's right
Him: F - you
Me: have a nice day!