I like to push the button to get a real person. Then I say, “Hi, I just thought I waste your time like you just wasted mine. Now go get a real job.”
A friend responded in that matter and then received calls every 30 minutes all night until he finally took the phone off its hook. They could have, but did not, repeat the treatment the next day.
On my cell phone when I receive a call from an unknown source, I push a button than replies, "I do not respond to telemarketing calls. If your message is legitimate, please text it. On my land line, I disconnect the call without actually answering.