I have a customer who says they didn't receive their package even tho USPS says it was delivered. I called the post office that did the delivering and they did a search and said the packaged was delivered to the correct address. It was geotagged at the right location. They sent the same delivery person back to check and they said the customers regular mail was still in her mailbox but the package was not. The post office said someone could have stole it and also suggested that the customer did receive it and are lying to get their money back. This is the first time this happens to me and I'm wondering if this is to be my fault? If it was stolen or she actually does have it do I still have to refund? I feel like once it's delivered and I did my part on calling the post office it's out of my hand and shouldn't refund but idk help!
At this point, it should be reported to USPS and it would be their fault if the customer hasn't received their package. Keep all the evidence that the package was delivered and that it was geotagged at the right location.
However, you should also consider the customer. Sometimes, it is better to refund the customer so that they will continue shopping with you. If it seems like this customer could make a future purchase, I would just refund to make their life easier, and to encourage them to think well of your brand. If this becomes a repeat problem, that is when you can turn them away and tell them to work it out with USPS. You may also want to switch to signature required or pay for insurance on the packages if this becomes a problem for other customers as well.
Ideally in such cases, it is very important that you keep insurance for the shipment that is sent. In addition, you should lodge a complaint in USPS with all evidence and then ask them to proceed with the investigation. Also, if the issue is resolved, it would be great if you can share some details of it.