Bought an item, paid for it and now I've got an unpaid item case?

I bought a pair of headphones and i'm pretty sure i did everything right. I wouldn't see any buying reminders telling me to pay, and the seller seemed quite happy in the emails I sent him about asking for a tracking number after i'd purchased it. That was about a week ago. Now, it says he's refunded the money and opened an unpaid item case on me. Either I'm reading my paypal reciept wrong or i seriously didn't pay him the money yet. Somebody help me! -Rex|||oh, it seems the seller recognizes the problem, i'll look through my paypal account and see what's happening :S