Visa gift card help!?

I want to put it on my xbox live account but it asks for a card holder name and when i registered it at the walmart website(where i bought it) it didn't ask for name and i don't know if this is the problem. i keep getting " We can't authorize the payment method. Please make sure the information is correct, or use another payment method. If you continue to get this message, please contact your financial institution." then an x appears beside everything.