Received call, ID was "Caller".  Did not answer, let machine answer.  They called right back.  Answered the call.  They asked if I remembered the health survey I filled out a month ago. I said "No" as I had not filled out any survey.  That didn't matter as I was still eligible for a 3 day vacation.  At this time I requested to be removed from their list but they hung up before I could finish the sentence.