UPS review: missing package

UPS lost an overnight letter envelope containing a visa and passport needed for a flight to Africa. We launched an investigation with UPS but with nothing happening, we did our own investigation since UPS's investigation takes up to 8 business days and tracked down the driver, his truck number and the address of the UPS facility in Landover, MD where the letter envelope is lost. However, that facility doesn't have a phone number, only the UPS general 800 number, and the reps at that number say that the UPS facility in Landover, MD doesn't have a phone number and the main UPS office can only communicate with them through an app. I begged someone to just give me the number of the Landover office so I could call them and ask them to please look around the conveyor belt as I was told by our local UPS office that the letter envelopes often get stuck in the conveyor belts or drop onto the floor around the conveyors. I just need someone to step up to the plate and actually look around. No one wants to do that and in the meantime, a very expensive airline ticket on Sunday to Africa for a university professor to get to students is going to have to be changed. But, the worst part is, his Dutch passport has gone missing in this package and no one at UPS wants to take any responsibility. Where is customer service these days? Gone the way of the dodo bird I'm afraid.