Got a text message from this number today. Saying I won a wal mart 1000 dollar gift card. So I called this number back and it says the v/m has not been set up yet.

I received the same text message yesterday from this phone number.  I did not call back the number, and did not try to go onto the website provided - www.wmart-voucher.com - since I did not want to take any chance of infecting my computer.