As a follow up to this thread, both myself and a coworker (who also had a package returned) spoke with the day manager at the Hilton.

Initially she was resistant, insisting that it was an isolated issue that just NEVER occurred at the hotel, until we pointed out that both of us had it happen on separate occasions within two weeks of each other.

She assured us that she would take care of it, and would personally talk to the receiving staff to make sure our packages. I also spoke with the front desk before checkout to let them know that I would have a package arriving after I checked out on Friday, and to please hold said package.

When I got to the airport, I tracked UPS like a hawk and called as soon as the status had changed to "Delivered". And it's a good thing I did - the ONLY reason my package wasn't once more returned to sender is because the woman on the phone recognized my name and ran out to grab it before they sent it back.

Sigh.

We're going to escalate to the GM tonight.

I've also made it a practice to put in a note on any package sent to me now that explicitly states "GUEST COMING ON TUESDAY, DO NOT RETURN TO SENDER". We'll see if it helps.