I would love to see an update. My guess from the details is that it 'disappeared' at Staples once someone knew that it was a high-value jewelry shipment. One employee talked about the expensive jewelry going out via UPS, and someone else figured it was a small package, easily concealed and taken, and UGGGHHHHHH. I really hope there was good video coverage of the UPS counter and package storage area at Staples.
Absolutely awful situation for OP and family. I hope they have gotten a happy resolution.