How to get a refund/replacement of this item ?

I got scammed by this seller. I purchased an item from this seller on Amazon in June (product link: https://www.amazon.com/gp/product/B09PGSZDHH).

A few days ago, the item stopped working suddenly and completely. I'm not exaggerating—there was no damage, no water spill, or any mishandling on my part. It just stopped working out of nowhere.

I tried reaching out to the seller and Amazon customer service, but neither has been helpful. Amazon claims they can't assist because the seller is a third-party vendor. The seller, on the other hand, says they only accept returns within 90 days, which is frustrating.

I feel terrible about this purchase. It cost me $1,092.58, including tax, and I really needed this item at the time because I am a student. Now, the repair costs are exorbitant.

Does anyone have any advice or ideas about what I can do? Do I have any options at this point?

https://imgur.com/a/KWK9M1Q

Updated Post : Update from repair shop

this is ***** from ***** with an update on your MacBook. Corrosion was found on several components of the motherboard once it was removed. We offer motherboard repair services for $680; expect completion within 4–5 business days. Please see the attached photos detailing the motherboard damage. We await your instructions on how to proceed. Thank you.

https://imgur.com/a/oAc2mDN

https://imgur.com/a/a88il9q

https://imgur.com/a/ejBdAF1