Who called from 9724759992

Appears to be an auto dialer checking to see if a given number (mine) is in service.  No one on the other end.

A man asking for me by name then launching into a sales pitch for some service. Told him my number was on the Do Not Call list and that his call was illegal. He replied, "Oh really?" and hung up. Called the number back, says it's disconnected or no longer in service.