When there is a problem with an eBay purchase paid through PayPal, the buyer should file a claim within 44 days of the purchase/payment. Otherwise, the buyer risks losing the protection given by eBay/PayPal to buyers.
At this late stage, it is too late to ask eBay or PayPal for help.
If you paid with your credit card, I suggest you call your credit card issuer (800 phone number on your monthly statement) and request a chargeback for non-receipt. It is a bit late but they may agree to process the chargeback.
In future, please do not wait that long to file a claim against the seller.
Also, checking your PayPal history for the last three months, you will find details of your payment to the seller including the email address where the payment was made. You can use that address to contact the seller.