Did you pay by credit card? If so, contact your credit card company, inform that you purchased a product from someone online, and that the goods were not delivered. You have made several reasonable attempts to contact the seller to no avail. It has been a considerable amount of time for a reasonable delivery period. You attempted to take the issue up with Paypal but they are unwilling to refund your money. Say the purchase was for sports equipment, only if they ask. Say exactly that, because if you give too many details (private seller, forum, airsoft/gun parts, etc...), they may not be willing to credit you.
If the action is approved, you will be mailed a letter that you sign and return in the postage paid envelope. Your credit card will then be credited the purchase price. Your credit card company will then take the issue up with Paypal who will then more than likely start taking action against this individual. This process applies only when paying by credit card however. It is good in almost all situations. Don't abuse it, or your credit report may be flagged and then you would be in trouble. Just do it in honest situations and you should be fine.