Did not answer call.  So far they have called twice.

I picked up the phone but didn't speak; usually that just leads the person or bot on the other end to hang up. This time, the man on the other end said my name twice and said he could hear me, then, clearly annoyed that he was not getting his way, he said, "I'm gonna call you ten more times tonight." (He did not, but I have received two more calls from the same number today and not picked up. No message.)

Calls many times a day.  Usually don't answer, but when I did there's no one there.

I've had about a dozen calls from this number, usually no one there, then today I answered and the voice asked for my significant other, I asked her to hold on for a minute and then asked who was calling... She hung up...

This is too much,  I get five or six calls a day from this number and with caller ID I ignore every one of them. Hopefully one day they will stop calling.  How do they get people's phone numbers?