This is a company hired by the NSF to do surveys of US Ph.Ds. Their form takes about an hour to fill out and I honestly don't have time but they keep calling me and mailing me and emailing me. This has been going on for MONTHS. This has actually crossed a line. I now consider this to be harassment.
If you still have the address to mail the completed forms to, you can send them a notarized "Cease Communications" letter via Certified Mail, Return Receipt. If they contact you after receiving such a letter you can now sue them for violation of your order.
It's a NSF-funded survey, executed by a private company, I believe. They have no ethics. Called my work and home phones several times after 11pm. I considered it a harassment since they do not offer people to opt out the survey. It's been going on for 3 months. NSF must have lots of funding on this to waste.
I also received these calls. They never left a message. The good news is : After I failed to return their survey a couple times, they just sent me a $30 check as a token of appreciation for me to complete the survey. And I gladly compiled.
They called three times in a row at 11:30 at night and woke me up. Once left a message, purporting to be a doctor at the National Science Foundation. Then hung up next two times when I responded. They call frequently but this is the first time at night. Sometimes the callers have trouble speaking in English. They say they are from NSF but I now believe it is a scam or people taking advantage of a call list to make harassing calls.