Got myself into a bit of a pickle and I want to make sure I handle it the best way I can. On a trip to Manila and I fly home in about 7 hours. I typically fly DEN-LAX-NRT-MNL due to cost. With the LAX travel waiver I reached out to United to see about getting onto the NRT-DEN direct flight. My company books my flights in economy for the domestic legs on one ticket and business for the international on another, this is all on one confirmation number (I am not 100% sure how this works and I have had it called both a broken ticket and illegal ticket depending who you talk to). The NRT-MNL route is on ANA. This obviously causes problems for doing things like SDC, however I called United to see about switching due to the circumstances. They were able to get me on the flight, however, said due to how the ticket was issued, I would need to talk to my travel agency to reissue the ticket. My travel agency (which is just our internal travel department) is telling me they can't do it either.

Thus, it appears I will end up in Narita with no ticket. I assume I will need to clear immigration and go to the United desk in Narita to get this sorted out (assuming I still have a ticket to get from MNL-NRT), however, I am wondering if anyone has any other experience or if there are better options once I am in Narita. Is there anything in place of a boarding pass I can use to go through the international transfer security area instead of clearing immigration?