I love getting Telemarketer Calls or any other scammers.
They're not intimidated by me telling them I'm with the Sheriff's Department, the FBI or any other agency.....except one.
Every time I get a call, I'm quick to answer: "Hello, this is Agent Eversole, IRS Collections. How may I help you?"
The person on the other end of the line, just about comes unglued trying to hang up.
On occasion, I'll get an apology, "Oops, I'm sorry" with a quick hang up. It's been the best and most entertaining way to deal with these idiots, because I've never had a repeat caller. 

Every time I get a call, I'm quick to answer: "Hello, this is Agent Eversole, IRS Collections. How may I help you?"
The person on the other end of the line, just about comes unglued trying to hang up.