Reverse Reimbursements

I sent in Items to amazon FBA about a half a year ago and all the items got lost, they agreed to reimburse me for the products, obviously the amount I was reimbursed didn’t even cover the costs of the products but since it was a small amount of products I accepted the losses and carried on.

Now after a half a year they suddenly gave me a reversed reimbursement that one of my items that a customer had returned was found but the amount I was reverse reimbursed didn’t match the amount I had refunded the customer so I got in contact with Customer service and they got back to me telling me that the reversed reimbursement isn’t due to a customer return but rather due to the fact that they found one of my lost items but now my problem is that the amount of money that was reversed reimbursed is about 3 times the amount of what I was reimbursed originally .

Any thing to do about such a story or is it just part of selling on amazon