GameStop refused to send my purchased slab and then resold it at higher amount

I purchased a PSA 10 2019 Moltres/Zapdos/Articuno 69 secret rare cert # 56565117 for $76.97 after discounts and rewards applied. The card was advertised for $89.99 on the website. Initially things were good and the card was prepared to be shipped, but then the order status was changed to pending. I called customer care and they said the card is on back order and nothing can be done. I checked my receipt which is linked to the exact card I purchased and it shows the exact same card with cert number is for sale again at $119.99. I told them about how my receipt is linked to the card I purchased and when I click the link it pulls up the card being shown for sale again at a higher price. I asked how the card is on back order when it is currently being advertised online as available for a higher price. The agent continued to just say they can’t do anything. I talked with two customer care agents and even had a supervisor call me back, all saying there is nothing that can be done. They changed their excuses and said the card I purchased was purchased by someone else while it was still available online for sale. I asked how can someone else have purchased it if it’s still available and they said it was a different card available online even though the PSA certs are exactly the same. Someone else now has bought the card at the $119.99 price and I’m stuck with a pending on back order. Video shows my order in progress with pictured slab in order linked to GameStop website, then reselling it at $119.99 price, and then my order being updated to pending and slab on back order.