I purchase many $$ thousands of gift cards every month for our plant bonuses. I get cards from Walmart and they come to me with a zero balance until I activate them with a special code I got when I made the purchase. This is what all retailers should do now days.
One time, I got a random shipment from Walmart that included $27k of giftcards. Unfortunately for me, they did not work. When I reported this to Walmart, they told me to just distroy the cards. Although I didn't do this, I thought it might be fun to just sprinkle them in a Walmart parking lot
I eventually ran them all thru the shredder (all 10 boxes of cards).