Unfortunately, you learned it the hard way.
On Paypal, the protection is valid for the first 45 days and on ebay, you can leave feedback for up to 60 days after transaction. Never pass these delays no matter what the seller promise you.
Have you paid with your credit card through Paypal or through your linked bank accounts?
If paid with credit card, you can contact the security/fraud/protection dept of your credit card and request a chargeback.
Otherwise, there is nothing much you can do...