Who called from 3479259807

in question i received a text for a 200 retail vocher 2 whare tho?

I got a text message saying I'd won a $200 gift voucher thanking me for visiting their site!  which I don't think I did.

text msg:
Thx 4 visiting our site
Call 1877-690-7090 to claim
Your free $20 Wal-Mart card plus $50 gas card,
gift code" rrv200

They won't answer returned calls, and will not take me off their list.

This number called my cellphone a few days ago and I don't recognize the number.  It's not a GA number I don't believe.  I'm searching for some answers to this mystery caller.

who is this calling my cellphone number?