I always ask telemarketers if I can put them on hold for a short bit, then I hang up the phone.
I always feel bad for telemarketers because it is such a hard job, and they're just trying to make a living. So I usually just tell them I'm not interested
But I have no pity for "Microsoft Tech Support" scam callers, and other scammers.
With those callers, I sort of do what you do -- ask them to hold for a second, but then I put the phone by my computer speaker and activate my "music on hold" icon on my desk top.
After the 200th call, I pressed '1'. I was greeted by a man speaking with a Hispanic accent. He asked if I wanted to get relief from high interest credit cards. I said, "No. What I want is for your company to stop calling me. I have no need for your services, whatever they are, so take my name of your list! Can you do that for me?"
His response?
"No. I can't. €u¢k you."
Great sales technique, huh?
The odd thing is, the caller ID showed my name and number for the incoming call.