Put an ad on craigslist that they're giving away something for free. Let them see how it feels to be bombarded with annoying/harassing phone calls all the time!!!
Stupid people keep calling for an Emily Platz. So I told them I was her, confirmed the information they gave me (just said sure) and got their company name. She finally said she was collecting a debt. This is Source RM. I had to ask her three times because she was deliberately mumbling.
She got ALL pissed off when I told her to stop calling our number, we had told them to stop calling multiple times, this was a business and this person didn't work here. She was still yapping when I hung up.