i have no idea which cards it is, amazon wont tell me.
Man, you've been reckless, and you have been warned before - don't go for cheap and keep a good accounting of the cards you buy and use.
Couple of pages ago I posted that you can be banned by Amazon and they can suspend/kill the orders.
Now, it might be late, but this is what you should do.
1. Create a spreadsheet to account for all Amazon cards you worked with - from whom, when, how much
2. You bought some from me - I can provide the info for every card I sold and receipts if needed, I even can ship you all physical cards at your cost.
3. I'm sure all the honest buyers can do the same
4. Check the value of every card bought by trying to add it to some Amazon account: there might be a difference between a valid used card (it says balance is zero) and fraudulent cards killed by Amazon
5. Once you complete #1 and roughly identified the cards which might be fraudulent - try online chat and beg Amazon to work with you, explain you've been cheated upon.
Back to the topic: I have supply of Amazon GCs, selling at 95.5%: $75s, $150s, some $500s
Mine are physical US-based cards; multiple payment methods, Zelle preferred, no Paypal