Inventory liquidated without our permission

I realised that we hadn’t received received any FBA returns shipments from Amazon in a while so checked the returns report. I saw that since the start of the year, all of our returns have been liquidated. That means we got 5-20% of the cost of the item returned to us and the item gets sent to a liquidator.

Only the returns which were classified as unsellable were liquidated, unfortunately this makes up a huge %. Customers tend to just say the product is faulty when it isn’t in order to get a free return. So these products probably just needed a new box, some probably only needed a relabelling.

We never selected that we wanted returns to be liquidated, it seemed to just be on by default. It has cost us thousands of pounds.

Seller support hasn’t been any use. Has anyone else had that problem? Or does anyone have any advice about how to try and claim this back? It seems really unfair that they can just take our returns for a fraction of their value without our permission!