Who called from 5713497794

This person is harrassing me and calling me at least twice a day and at 10:00 p.m. at night saying that I won a prize of so much money and they want $495 dollars.

I have received several calls from this number and they never leave a message. It shows on my caller ID: VA, USA 571 349 7794.  I returned the call and it says that it is not in service?

Get calls from this #(571-349-7794)  How to stop thes calls. They call evary day . We ar on do not call list.
What can we do.

Get calls from this #(571-349-7794)  How to stop thes calls. They call evary day . We ar on do not call list.
What can we do.

I have 2 cell phones which are not related, This number keeps on calling me also ! WTF is it Where the hell is a 571 area code ?