Super simple 5 minutes that can get you back a ton depending on your size.
When dealing with FBA, sometimes Amazon disposes of your inventory. Sometimes it's because it's defective, but sometimes it can be because the warehouse or a customer damaged it. Sometimes though they will dispose of your products without first getting your permission or giving you a chance to inspect it. When this happens, you can politely ask for a reimbursement refund.
1) Go to "Reports" then "Fulfillment"
2) Click "inventory adjustments"
3) Set to "destroyed" and as far back as you have been selling
After that, simply start a new case with Amazon politely asking for a refund of these products that were destroyed. You can use the transaction ID's, or simply just copy and paste the exact URL of the page you are on.
Easy way to get money back. I got a couple thousand dollars back Update 2018* - Ok I ended up receiving a bunch of PM's about this. Turns out there are A LOT of other ways that you can get refunds from Amazon as a seller. Sellers can get reimbursed for a lot of different reasons. Incorrect refunds given to customers from Amazon support, lost inventory, incorrect removal orders, etc. It's a bit more complicated to find out ALL of the ways to get reimbursed that what I wrote above, but there are a bunch of Amazon reimbursement services like AMZrefund and Refunds Manager that make it easy.