Amazon make mistakes all the time. Unless you’re diligently calculating your outgoings every day, you might never know. Essentially, you could be entitled to a refund if Amazon are responsible for events including:
Items destroyed without your request or permission.
Customers refunded more than they originally paid.
Orders for which the weight fee or dimensional fee has been overcharged.
Items lost or damaged in Amazon’s warehouse that have not been reimbursed.
Replacements sent to the customer, but the original item was never sent back.
Amazon saying it has reimbursed you for a return when in fact it has not.
Some of these might sound unlikely, but they really do happen! Amazon do sometimes lose or damage items in storage, and they do refund items which are never returned, for example.
The scale of Amazon’s operation is enormous, so losses and damages are bound to happen from time to time. These errors, if undetected, lose you money and impact your bottom line. Remember that using FBA makes you Amazon’s customer, and you are well within your rights to be refunded for any losses or miscalculations.
Because these problems happen out of sight, and can only be found by downloading and cross-referencing various reports, it’s very easy to miss them. Many small losses really add up and over the course of the year you could be owed thousands of dollars or more.