Exactly as Jools states, if you pay by credit card but never get the item you can claim against 'Non-Receipt of Goods'. It's a purchase clause that credit card companies are legally obliged to include as part of the distance selling/purchasing regs.
I'm not sure how long you get to claim, but I've got money back for a camera from ebay that never turned up, and cash that never came out of a cash machine. One was in 2001 and t'other in 2003, but I doubt much has changed since then.
Approach Paypal first and then your CC issuer. If they give you any grief go straight to their complaints manager.
Good luck!
Ali