When my husband and I got new cell phones, Verizon wouldn't let us keep our old numbers (we went to pre-paid because it was cheaper). So we got new numbers that had obviously been "recycled" from previous use. We were getting telemarketing and scam calls out the wazoo, at all hours of the day.
I accidentally stumbled upon a hilarious idea that might stop them, and it actually worked!
1. Put the number on the Do-Not-Call list.
2. For my voice mail recording, rather than saying "You have reached blah blah, please leave a message", I recorded this instead:
https://www.youtube.com/watch?v=2BVbyCZXc5s
I told my friends and family about it so they wouldn't think my phone had actually been disconnected, and they can still leave a message normally after the "greeting" stops playing.
The scammers and telemarketers hear the "disconnected" message and hang up, and since they think the number isn't valid, they take it off their list. I suspect the computer-dialed numbers "listen" for this message, and mark the number as being disconnected.
Within just a few weeks, the calls STOPPED.
To take care of any repeat offenders, I downloaded a free app called Mr. Number that lets you block calls. You can choose whether to hang up, or to send the call to your voice mail. I chose voice mail, so they go straight to the "disconnected" message without my phone ever ringing. Obviously the app wouldn't work on a landline, but it works great for cell phones.
