They picked the wrong one to mess with because I report.
I can tell you that the FCC does contact them and does put them through all kinds of paperwork and an investigation. The fine is $10K.
Just write down every time they call- time and date. Once you get three, that's good enough to report. You don't even have to talk to them. The fact that they are calling you when you are on the registry is enough.
REPORT THEM! It's easy to do.
I had another one of these jerks tell me that there isn't any such thing as the do not call registry anymore. I guess he's in for a surprise.
CID said "Service Call". I picked it up and it was a recording of some perky female voice telling me that as of January 3d, electric service was deregulated, and I can save some percentage on my electric bill. I hung up on it at that point, so I can't tell you who or what it was.
Note that I am on the national DNC list, and robo-calls are banned anyway, so that's two violations of the law right there.