The only thing I guess you can't do with the gift card is pay the installment billing down payment/tax on sprint because it has to be done before activation on a easy pay line. You can use the gift card toward the tax on verizon or AT&T or there Next or Edge plans and also use it toward any 2yr contract or outright price. You might of encountered a new employee who just didn't know. There's a lot of stuff for a mobile associate to remember. We have the prices change on us every Sunday morning, different promotions all the time, carriers changing there plans around, and then if best buy itself changes a policy. After being there almost a year I'm use to it but for someone new it can sometimes be a pain at first and hard to keep up if you don't get enough hours.