It sounds like a buyer and Amazon put you in a catch-22 situation. If the buyer initiates a return and then puts in an A-Z Claim you will automatically lose the A-Z Claim and take an ODR hit if you properly refund the buyer for the return. When this happens, you can't refund the buyer, the A-Z case had to be closed so that you can then refund the buyer without an ODR hit. In the future in this situatio, you can try messaging the buyer and explaining this so that they will hopefully withdraw their A-Z claim, and you can try adding it to the A-Z case explaining that you need to refund but can't because of the open A-Z case and to please close the case so that you can refund the order. No guarantee it will work, though. Amazon may just decide against you and count it against your ODR anyway. It's extremely unfair but just a situation you can get into on Amazon due to impatient buyers and Amazon's system. I think the fact that some orders are refunded at first scan cause some buyers to file an A-Z claim right away for those that aren't which contributes to this situation. Sadly, I think it's too late for this one, you're just stuck with the ODR even though you really didn't do anything wrong except not knowing that you couldn't issue the refund because the A-Z claim was open since to Amazon's system that is an admission of guilt.