eBay's responsibility when receiving such a message from a manufacturer is to forward the information to the relevant buyers.
If you are out of time, that is 30 days have passed which they have here, neither eBay nor the seller is responsible for any refund.
You may still be in time to try a refund from your payment provider, if not, contact the manufacturer of the item, see if they have any steps you can take now.
@sunflowerface1