Who called from 7138937021

Just got a call from the number.. My caller ID said unknown caller

Received a call from this number Caller ID shows no name.  We do not answer the phone can't be bothered with such calls, they are just wasting their time as we will not answer so they might as well give up.

I called back. Houston Chronicle. Why does a telemarketer hang up? I didn't ask him.

They called my number 15 mins ago. I didn't pick up the phone then added this number to the block list on my Panasonic phone.

I am on do not call list, yet they call frequently.  They hang up before message machine comes on.  Annoying, pest.