I'm sorry to tell you, but there is no PayPal Buyer Protection on purchases when you use PayPal as a guest. 

From the PayPal user agreement, just so you can confirm this information:

"S12.1 You may be eligible for the PayPal Buyer Protection Policy if all the following requirements are met:

Your payment is made from your account and not directly from a Credit Card processed through our Website Payments Pro or Virtual Terminal service;"

That being said, all hope is not lost just yet. You may be able to initiate a case via eBay if the original estimated date of arrival was less than 30 days ago, as there is no clause that excludes PayPal guest payments from eBay's Money Back Guarantee - in you purchase history on ebay, next to the item and on the right, should be a dropdown menu where you can select the option to report the item wasn't received. If it directs you to PayPal, try instead going to the resolution centre, link: http://res.ebay.com.au/ws/eBayISAPI.dll?ResolutionCenter with the item number, or even the Help & Contact page (link to that is up the top of every eBay page) as usually all of your recent purchases will be displayed there and you can click on the one you need help with.

If you're not able to find resolution with eBay, contact your credit card provider to discuss your options, as you might be able to initiate a chargeback.