Oh no! Sometimes this happens and is a big bummer. We have no control over a package once it leaves our warehouse and handed off to the mail carrier.
We recommend that you check in with any family, friends in the house and neighbors to see if it was put aside or delivered to the wrong address by accident. If you live in an apartment complex or school dorms, check in with the front desk of your building. If all of that turns up nothing, give your local post office a call to see if they can further help you locate the package.
You should also contact your local post office as they are stating that they made the delivery as per the USPS tracking info on USPS site. That info and status is updated by USPS. For questions regarding your USPS shipment, you can call USPS Customer Care Center at 1-800-ASK-USPS (1-800-275-8777).
Each post office in United States has different practices on status updates. Some post office marks completion in batch, and that can occur either before or after delivery. Your local post office can provide info on how they do it at their branch for your area. If it is done prior to delivery, then they can tell you how long it can take.
If you have security cameras, you can check to see if someone stole your mail. Depending on what you suspect can occur at your local vicinity, you have other recourse, such as requesting local law enforcement to investigate or request the US Postal Inspector to investigate. If you have a case opened with either your local law enforcement or US Postal Inspector, you can contact us and provide us the details and we can check into options. If US Postal Service retract the delivery status, we can also then send replacement based on lost mail. We would provide replacement if USPS status doesn't indicate delivery, at which point we will consider the shipment as lost.
For more assistance, please see our guide on Mail Issues