Called twice in last week, I did not answer, they left no message either time.  I called the number back, recording says it's CTC Teleservices and does telemarketing and surveys for a "wide variety of companies" (their words).  I know it's a bad idea, but pressed "5" to get removed from their calling list (yeah, I know, I just confirmed my number is active LOL, but figured I already did that by calling them).  Also blocked them, so instead of using this number they can now call from the infinitely slightly different versions, no doubt.