unknown number. called ..left no message

Same here. Called it back and all I got  a recording saying something like "if you are calling this number than we are attempting to contact you about a market research survey...". I tired once before I got the actual recording and got about 2 seconds of the recording and then it jumped to a busy signal.

Got a call from this number

Received call from 1-567-248-2093 left no message.  I have signed up for "no solicitation calls".

I never, ever answer any call from anyone who won't announce who they are. Stuff it, "Caller."