Caller "blah, blah, blah. What's your date of birth?" I replied with a few cuss words and click. They called back the following night without saying a word. Blocked the number. Never give personal information to unknown callers.

I didn't pick up. Caller left no message but they listened to my recording and let VM beep before hanging up.
Irritating has heck. How do they get our numbers???

Left partial message; all I got was her last name Summers, and then she hung up. Caller Id said it was a research center.

This number calls 3 & 4 times every evening up until 9pm.  We do not answer calls of numbers we are not familiar with.  Does anyone know what this number is calling about

The company is called Intermountain something.  They're doing political surveying.  They call repeatedly if you don't answer.  They say if you answer their brief questions, they won't call again.