I think you may have to accept, as we all will, that to sell on Ebay now means, there is a small chance you will have your item, your money, or both stolen, through the Paypal system. OR that people will make returns for no good reason at all.
YOUR return policy means absolutely nothing now, with Paypal and Ebay's rules. Just tell anyone who wants to return something to go ahead and do so, and when you get it back refund the money. It's much less hassle to just pass the cost of the few items that people do jerk you around on, on to the rest of your buyers via a shipping and handling surcharge. (Insurance companies do that all the time, so do variety stores.)
You have to accept that what YOU want as a return policy does not matter in the new Ebay. If a customer complains they can chargeback the item, leave you a negative, and low DSR's, greatly impacting your business.
YOU can't do a thing about it now. There is no control over your own affairs on Ebay anymore. Big brother ebay has seen to that. If someone is not happy, you will lose money, that is all there is too it. Welcome to the new Ebay!
We've had 2 returns this week, on $70 worth of china, on which there was nothing wrong at all. In 4 years we only did 3 like that.
Buyer's remorse IS now a valid return reason, and you can't do a thing about it.
Sorry to be the one to break it to you.