Replacement AirPod not able to return

i have purchased a replacement AirPod for a list one- between the time I have placed order for missing AirPod and received replacement - I did find the AirPod I was missing. I contacted Apple support and the Apple advisor told me replacement AirPod is a non-refundable or exchangeable item, that this is company policy. I am not doubting it is policy , but there is no where on Apple website that states a replaced AirPod is a non-refundable purchase. I am trying to get a return Authorization labor for a refund, but Apple rep says they cannot assist me.

Has anyone else run into this situation. I just want to return unopened right AirPod for a refund. Please advise me the best action to resolve my case