For a while I was verbally abusive to anyone who spam called me. It seems to have worked. I get significantly fewer spam calls than everyone else I know.
You mad, Bro?
I get maybe one spam call per week. I have a Google Voice number that I use for all business transactions. Only my close friends get my real phone number. I think the spam filtering of Voice helps reduce spam calls.
Yeah, my mom gets a lot. She’ll say, I don’t recognize the number but what if it’s my doctor or someone important? I tell her, they’ll leave a message. Then she’ll say, should I call this one back and tell them they have the wrong number? 
This is how you get on and stay on their lists, Mom!!!
Actually, probably not. For whatever reason, I get a shit-ton of spam calls, which I always ignore or decline. But sometimes it’s a local number, so I occasionally dial that number. It’s always a ‘spoofed’ number, and the call doesn’t go through. Instead, I get a message from Verizon telling me that the number is not in service.
I get a half dozen spam texts every day but only a couple phone calls each week. I never have interacted with them except to block the numbers. This started a couple years ago. God, I hate them!
My greeting message says, “If this is a business call, and you want a callback, please text me or leave a voicemail.”
The really fun ones are the automated confirmation calls - from a doctor’s office, for example - that want you to press a button. So you get a voicemail demanding that you press ‘1’ to confirm your appointment. 