[binarycrusader]

Having gone through this myself, the best way is to always go directly to a local post office and talk to the specialist there, or call the local post office directly and ask to speak to the right department.

If you're kind, and exceedingly polite to them, and are as understanding as possible, they'll be incredibly helpful in return.

The people that deal with lost packages and lost mail are used to being yelled at, berated, and treated poorly, so they often react surprised and helpfully when you go out of your way to be as nice as possible.

Most importantly, the best advice I can provide is to have all of the information you can possibly provide written down first (preferably typed so they can read it easier), along with a detailed timeline, and copies of any supporting documentation.