I got a gift card from Game stop and I want to know if there is a way that I can buy stuff (Black ops 2 DLCs) with the money from the card.
is your gift card a PSN gift card, or a game stop gift card? if it is a PSN gift card you recieved, then you need to redeem it on your PS3, which will then add money to your account. Then you can purchase whatever you want off of the psn store.
if it is a game stop gift card, then you have to use it to purchase something from gamestop.