Me too!!

Called three times in one day, not leaving a message or responding when I answered on the second ring

Nomessage

Number not in service on call back. Called 3xs today

First time I answered with "hello" and (of course) they hung up without any reply. Just a few minutes later, they called again, so I "answered" with saying anything.  After a few seconds, they said something, so I replied and they said I had requested information on colleges (which, of course, I had not). So I said I was not interested and hung up on them.  Their number is now blocked from coming through, so I won't be bothered should they persist (which clowns like them like to do).