Sellers are no longer allowed to charge a re-stocking fee.
About all you can do is not allow remorse returns. This, of course, does not stop a buyer from opening a NAD claim, which eBay does not require the buyer to prove, and you as a seller will have the option to refund without having the buyer return it, but you will not be able to refuse to refund.
eBay will tell you "It's the cost of doing business".
The only other option is for Top Rated Sellers, who are allowed to deduct a portion of the refund if there is a issue with the return. I've only had to use that option once, and it was not just over the PP fees. That option is not intended as a work around for a restocking fee, but for returned items that have been materially altered without approval.
