Retailers and gift card issuers will be more likely to work with customers on recovering or replacing lost gift cards if there is proof that the gift card story is legitimate. That proof comes in the shape of knowing the gift card number, when it was purchased, the dollar amount on the card, and so forth. Without that information, asking for a replacement gift card is like asking for a replacement 20 dollar bill…not likely to happen. Better to avoid that situation entirely by keeping better track of the gift card in the first place.
As for my brother, he is out of luck. He didn’t treat the gift card like cash, he didn’t write down the number or get an activation receipt and he hadn’t registered the gift card anywhere. All he got out of this particular gift card is a lesson learned.