Got a call from this number. Said hello 3 times. Finally heard a recording saying "Goodbye"

970-568-5246 called and then when ai returned call it said not in service.

This number shows up on my caller idea and then when I say "hello", they just sit there, and then I hung up.  When I called back, I got a recording that says something like "This number is no longer in service".  This was on the very same day that I received the call.   I live in Fort collins, Co.

Got a call from them a number of times, leaves no message. Number on phone shows a Fort Collins number, but when I looked it up, shows to be on the western slope.