Who called from 5152001016

Damn fools, wasting my time.  I called the number and got a recording:  Please press one to be added to our Do Not Call List.  It is their responsibility to check the Federal Do Not Call List, and recorded messages are not allowed either.  Time to make a complaint - Only wish I could talk to them.

Are they checking for valid phone numbers, so they do a test call?

That would be my guess.

Pressing one most likely tells the caller that this is an active phone number and instead of being put on the Do Not Call list, you end up getting unending calls from them and other crooks.

Just got a call from this number about 30 minutes ago. No message left. I'm guessing it probably is a validation type deal.