eBay says I paid, but no record exists?

I recently purchased an item on eBay. I have a paypal account set up with my checking account. I paid as usual, I even received a notice saying I had, but no conformation email ever arrived and the item is still marked as needing to be paid. My paypal has worked flawlessly prior to now, I have the funds, but no record, except that notice , states I have paid. My bank statement does not say otherwise, there is no pending amount or anything and paypal has no record either. I contacted the seller and she stated that she has not received any payments. What is going on? How may I proceed to remedy this situation?