You could start taking photos during the inspection of the returned item and before sending it, send a photo to the customer to confirm it’s what they ordered? You could establish a policy where you offer posted discounts (and lose money) if items aren’t as described? You could involve manufacturers in the re-certification process such that for high value items there’s maybe an extra shipping expense and time delay to market but the item’s quality could be verified before resale? You could strictly accept and sell only new items, putting returned or third-party FBA items in less efficient markets but completely isolated from the main market of trusted goods from known validated sources in your supply chain?