Firstly, don't ever pick up the phone when you don't recognize the number. Secondly, don't waste your time with the Do Not Call registry. It's absolutely worthless. Thirdly, go buy yourself a call blocker. It's most beneficial.
Fourthly, have a wonderful day.
I keep getting calls from the "National Renewable Energy Center". The males that call are rude and obnoxious. I have told them repeatedly to take me off their call list. There is one man, whose voice I now recognize, that sounds like he's slurping his coffee and saying all sorts of weird things just to try to keep me on the line.