Itunes card code does not work!?

I am really really pissed right now. I have to get on a plane tomorrow and i'm worrying about getting this card into my account for my trip. When i type in the code the error message that comes up: is The code you have just entered is not recognized as a Free Song Code. What in the world its not a Free Song Code. I have many words i want to say right now but i am going to bite my fingers Just tried a different card that was in the Costco set i bought and it worked so it's just that ONE card. I don't know why it comes up as a Free Song Code

Help would be great! Don't want to blow $15!