Amazon added two ways to help delight customers and grow your business, 1) The Customer Returns Tool and 2) Free Replacements For Customers.
Customer returns tool
Amazon has added a tool to the FBA customer returns report page to give you greater visibility into reimbursements and customer returns. To quickly see whether you’ve been reimbursed, if you qualify for reimbursement, or if Amazon is still waiting for a customer return to evaluate:
Go to the FBA customer returns report
In the Important Message section, click input the order ID here to access the tool
Enter a Customer order ID to check your reimbursement status
Important: Before requesting a reimbursement, review the FBA customer returns policy.(Login required)
Amazon free replacements
Sometimes customers want a replacement for an item rather than just return it. With Amazon free replacements, customers can opt for a free replacement instead of waiting for a refund and then buying the same item again. Amazon ships an identical item (if available) from your inventory when a free replacement is requested.
Note: When a customer chooses a free replacement, you will see the item deducted from your inventory and a sale for $0 on your Customer Shipment Sales and Payments reports.
The customer has 30 days to return the unit (if possible), or they could be charged. Once the original unit is returned to Amazon, Amazon will evaluate it. If eligible for reimbursement, you will be reimbursed within 45 days of the customer replacement request.
Reference: Reimbursements(Login required)