Accidentally Ordered The Wrong Item

I am getting killed with FBA returns lately and it is absolutely destroying my business. I buy and sell wholesale products and the margins are already paper thin. Most of the returns I get are at no fault of mine but are usually for unwanted items and accidentally ordered the wrong item. More than half of the returns I get are opened or damaged by the customer. Why on earth does Amazon give full refunds to customers if hey return an opened product just because they don’t want it? I understand for returns that are damaged or defective but there is no reason to return an item opened because you ordered the wrong thing. Is there anyway for me to get any reimbursements for these type of returns? Haven’t been able to get a decent answer from anyone.