Who called from 4072050304

Its called Spoofed caller ID..
phone spoofing explanation
http://en.wikipedia.org/wiki/Spoofing_attack
http://www.fcc.gov/guides/caller-id-and-spoofing

Has called our business 2 or 3 times.  Comes up on caller id as 'not in use'.  I just hit the speaker button twice really fast that way it answers and disconnects immediately.  After all, why should I say anything if it is not in use.

This number has called twice in the last 10 minutes. It says "NOT IN USE" and no one answers the line. I am sick of this, it's a waste of time.

We keep getting calls from this number.  The called id says Not in Use!  But no one responds when I pick up and say hello.  What's the purpose?

I get the same call daily.  They call and ask for the owner and when I ask if somebody else can help (because the owner isn't available) they hang up.  This has been going on for months.