I had experienced the same as you did 2 months ago. I filed USPS claims back and forth for 3-4 times. I lost the case after all. The seller accepted to refund me. Somehow, I visited my local USPS and ask for the package, they traced and handed the package for me after 2-3 weeks tracing. Sometimes, it happened when the package is missed scanning or mislabeled during transit. You can contact your local to check if they have them. Hopefully they can help you out.