Bests & Worsts Reviews from Amazon

I purchased a gift card for almost $700 to redeem for a large purchase and several other smaller items. I went in to redeem my gift card and the balance is now $0. Essentially, Amazon is informing me that gift cards are not secure and that they have no liability and are not required to refund the monies. My account has clearly been compromised and Amazon is aware of this and still refuses to do anything. I have contacted my bank to dispute the charge per the Amazon representative. So disappointed!