did he cancel the first listing? or open a non payment complaint? or did he unofficially make a 2nd listing, as if he had 2 of the same item.
basically he owes you 2 items (if he did not cancel the auction in an official manner). you should have 2 listings in your auction history.
pay for both.
then if he only sends you 1 item use the reference number in your ebay history to ask for a refund on other first auction.
Contact the seller to see if they are sending you the item. Otherwise they may have relisted because they thought you were a non paying bidder (and there's tons of them). In that case, the seller needs to refund you. You might check your PayPal account, the seller may have not accepted your payment or already refunded you. Your PayPal account will show you the status if the transaction.
Contact the seller.
Open an "item not received" case. Then stay off ebay until you understand how it works.
I won an item on ebay, it took me a couple days to pay for it, but i eventually paid for it, during those days the seller relisted the item, i paid before the seller's relisting ended, and i under purchased items it said i paid for it, but there is no tracking information (if this helps, i bought it the 19th, now it is the 22nd) there is no information at all, will i recieve this item?