How do you effectively manage MFN returns on Amazon?

Many of the returns I get feel completely frivolous, with buyers giving excuses like “ordered by mistake” or “wrong size.” The frustrating part is that less than 50% of these returns are ever actually shipped back to me. When I contact Amazon support, I get conflicting advice on how to handle return authorization requests. I have just ignored them completely.

Is it even worth messaging the customer to try and resolve these issues directly? Honestly, the return portal seems pretty useless. The only productive thing I’ve found is managing A-to-Z claims when buyers say the order wasn’t delivered, even though I have proof it was. I get refunded on those.

Does anyone have a practical system for managing returns efficiently? Also, when a buyer generates a return label (at my expense) but never ships the item back, does Amazon refund me for the cost of the unused label? Any insights would be appreciated.