That's quite a long time to wait. I'd open an unpaid item case. I believe that is the correct name for it. You should see it in the drop down options beside the listing information in the "Sold" section of My
ebay.
Someone with more selling experience on
ebay can correct me if I'm wrong, but I believe this sends a notice to the buyer and gives them 4 d to pay for the item. After that, you are able to cancel the transaction and re-list the item.