Trying to get Annihalation Map Pack for Black Ops?

I'm trying to get the new map pack for call of duty, but the only money I HAVE is on a vintage stock gift card, but vintage stock is being a cheap a** and doesnt sell microsoft points. Yay! Just MY luck. Is there some way I could get the money off of the gift card and into a form of real cash? Plz help Your average Fourteen year old Xbox junkie.