I am seller on the Amazon platform

I am seller on the Amazon platform. I sold an items and it was collected by the courier and delivered to the buyer. Amazon initiated a refund back to the buyer claiming that the item was returned to me. I file a SAFE-T claim disputing the refund and they declined my dispute. I took the liberty to verify with courier company and they provided me with proof of delivery and proof of identification of the buyer who receive the item. I appealed their decision and provided them proof obtained by the courier, they still claim the item was sent back to seller. Amazon does not value its sellers. They reverse payment without proper investigation, always in favor of the buyer and cause losses to sellers. I have been reappealing their decision and they respond with the same message. It seems the appeal goes to the same person who denied it because how else are they sending the same response as the previous person.I will go as far as legal route with this and I will move my business to other competing plartforms.