http://resolutioncenter.ebay.ca/
Go here.
Open the case.
If you cannot open the case as a guest, which seems odd to me, go to the credit card you actually paid with (Paypal is just a mediator) and call the 1-800 customer service number. Ask the clerk about a chargeback.
She will need the date of purchase, the transaction numbers (eBay, Paypal and your credit card) the payment amount and possibly some other information. Have it handy.
While you have 45 days to open a case with eBay/Paypal, your card has a longer deadline.
Also how long has it been since you ordered?
It takes about 10-15 days for items to arrive from Europe.
It takes about 15 to 20 days for items to arrive from Canada or the USA.
It takes about 30 days for items to arrive from Asia.
Until that time has passed, relax. But mark them on your calendar.