How to get rid of Telemarketers and debt collectors

We had a telemarketer call the other night just as we sat down to dinner (isn't that when they all call?) and I just wasn't in the mood for the call. He introduced himself by name and company name and I hit him right back with, "You know, we're registered on the 'Do Not Call List' and now that I have your name and company you're going to be basis of my complaint call to them!" Heard nothing for a few seconds, then only stuttering and stammering before I hung up the phone.
Other times I ask them, "Can you hold for just a second?". Then I just set the phone down. I finally hang up when I start hearing the sounds of a disconnected call from the phone.