firstly go into your paypal account and refund the buyers payment. Then in ebay if the buyer is ok with it send through a transaction cancellation, they will need to agree to it and you will get your FVF back.  If you don't know how to send a cancelation go into your sold section find the item then over on the RHS of page click on the drop down menu and select resolve a problem. then it will open a page then select you wish to cancel.