You didn't buy from eBay, you bought from a seller on eBay. All purchases are recorded perhaps you purchased as a guest. If you purchased as a guest those transactions won't show in your account. Only the guest account.
Get help if you bought as a guest
If the purchased was made more than 90 days ago you will still find your purchase but you won't be able to open it to see your order details, because eBay doesn't keep sold or ended listings on the platform for more than 90 days.
You also won't be able to return orders more than 30 old since you only get up to 30 days to return from the date of delivery.
If your purchase was less than 180 days ago you can file a return through PayPal if that is how you paid or through a chargeback on your credit card.
