Work with the buyer to reach a mutually agreeable solution with regard to this transaction. How you decide to proceed is ultimately determined by you and your customer service policy, but all sellers are expected to demonstrate a high level of customer service.
Below are some ways you can handle this situation. Regardless of which option you choose, the buyer may still post negative feedback for the transaction.
Issuing a refund for a product that was not received is usually the most customer-friendly solution. If the original order arrives after you've made a refund, Amazon can recharge the customer (with their authorisation). For information about refunds, see Refunding Orders.
If you choose this option, please be aware that your buyer may file an A-to-z Guarantee claim.
While this may be a financial loss for your business, it is good customer service. If the buyer ultimately receives the original order, you can work with them to facilitate a return.
In some situations, if an order was lost in transit, you may be able to receive assistance from your shipping carrier. If you purchased package tracking or insurance, the carrier may be able to assist in locating the package or filing an insurance claim. If tracking information was not obtained, there may still be options available from your carrier to help locate the package.