[78-L] An e-puzzle

[S&R Pinsker]

Back on 10 July I won an item and paid promptly via Paypal.
On the 13th, I received an e-mail from Paypal that the seller had
refunded my payment. He has not answered messages requesting
an explanation and I am still being told that I need to pay for one  
item.
Any ideas?
My one more charitable thought was that he had some kind of accident
and a family member or friend was able to kill the deal on his behalf.
The only suggestion from the "harbormasters" is that I leave negative
feedback but somehow that doesn't seem quite right.
Bob P