Fake buyer order and refund on non-returnable item while amazon taking no action

I am getting many orders from buyer where a buyer orders in multiple quantity and with multiple orders, the products are non-returnable products, buyer are still taking refund of the product as soon as they are delivered the product, amazon even cuts more amount than the original value, because of this we loose the product as well as the money, also because of these buyers fake claims amazon will put policy violation strike on the account and then in turn we'll loose the ranking resulting in more loose, we have a strict qc team that check each and every order before packing and they don't make any mistake while packing still these buyer are getting claims and amazon is even giving them claim happily, and they don't have any claim policy for these products that will simply come on our head, it feels like amazon has their leg on our neck, also the support team says that there is nothing that can be done, why amazon, if sellers are investing huge amount of money then this should not be how we should loose it