Unfortunately, the first step is to contact the carrier to request a "geolocation scan" so that they can try and track down the package for you. We have seen too many times that the carrier will scan items early, and then they show up a day or two later because they don't want to get into trouble for a delay on delivery.
After that has been completed, and truly shown as mis-delivered or lost by the carrier, please contact us through our platform to provide the information from the carrier and to see about finalizing a resolution, such as a new shipment or refund.
If you purchased marketplace shipping insurance on the missing order, please reach out to us directly for a resolution.