The guy left a message like he knew me:  "Monty!  Hey Monty!"  ... then hung up.  Some telemarketers were doing this type of 'familiar' calling that I worked with years ago.  It makes people pick up their phone sometimes (so the sales pitch can be made).  
Unethical and tricky.

Don't you know whose number this is but it's out of Boulder, MT. When you call the number you just get out on hold with music!

Called and said Bad Connection - Tried to call back put on music hold..... and hold... and hold