support tells me that 650$ of overscratched gift cards have already been redeemed by someone else

i’m actually livid and i don’t know what to do. i bought 650$ of gift cards and all of them were missing the last few numbers. i sent support and email and after 2 weeks of emailing back and forth, sending images, receipts, and hand writing a code on the receipts, they told me someone else reached out with the same details and redeemed it first. this is IMPOSSIBLE unless razer gave 2 of the same gift card out. this is an amount of money im willing to look at taking legal action against razer for. i need a phone number or a supervisors email or some sort of direction because i spent an entire paycheck on a gift for my son and i am not just going to let my money vanish. they had me hand write a code onto my gift cards and receipts so i have no clue how they could possibly imagine someone else bought these cards. Please someone help im livid this is a lot of money for me