You can file for a refund with paypal within 30 days of the end of the auction.
The seller will have to provide a delivery confirmation number to Paypal or a refund will be issued.
HOWEVER, if you paid using your existing paypal balance or from fund taken directly out of your bank account and the seller no longer has funds in his/her paypal account, then you may just get an email from paypal telling you too bad. They can't give a refund if the seller has already withdrawn the payment you made. That is what happened to me once.
If you paid via credit card, then you can dispute the charges with your credit card company.
Good luck. I hope you either get your vouchers or your money back.
Sometimes Paypal can really stink when someone scams you.