Granted A-to-Z for a partial refund

Hi there,

A client returned a FBM order shortly after it was delivered. When the product arrived, the packaging was not damaged but the product had severe scratches on it and it was basically impossible to be resold as a brand new product. We deducted 50% from the refund and submitted a thorough report on Amazon (as part of the "Partial refund" page) attaching 10 photos of the packaging and the product. The buyer opened an A-to-Z claim and got the full amount refunded. We appealed the decision but we were not surprised to hear back from Amazon that the appeal was denied. We now have to sell the product for less than 50% of what is worth meaning we will take the 200+ GBP loss. We don't know why Amazon provides the option to issue partial refunds and provide descriptions and photos when they don't consider this at all. It is really frustrating because clients can return products in whatever state they want and we can't do anything about it (at least for FBM orders). We've had issues with returns before, where clients return used products in a terrible state and we as sellers can't do anything about it, but take the financial hit. This is getting hard to bear in terms of costs. Any suggestions anyone?