Who called from 3144499939

Same phone# called 1-2 rings hung up.   4/24  4:19pm

This number calls, when answer, no one says nothing then hang up

Called 1 minute ago, (8:52 4/30/15) It didn't ring even ring once, before the caller hung up. No voice message.

Called on my cell phone. Rang once. I didn't recognize number so didn't answer.

My number is unlisted and on  the Federal Do Not Call Registry.
Didn't recognize the number so didn't answer it, did not leave a message. (5/2/15 @ 4:11pm)
Will not return unknown calls.