This, and also "if you had travel insurance use it!" are frankly useless victim blaming comments.

People on flyertalk typically buy dozens of tickets, and I'm sure no one is sitting around reading the entire fare rules or buying insurance for every single trip (and this seams like a fairly standard roundtrip US-Asia which no one typically would read the entire rules or get insurance for - its not an expensive safari or antarctic cruise).

In general, people understand that tickets are non-refundable, and that they might have to pay a change fees with fare-difference to make the change. Outside of basic economy tickets which are spelt out (not the case here), there is no reasonable expectation that you wouldn't be able to pay a change fee to make the change.

OP, you can probably wait to see if there is a schedule change by AA, and use that to request a change? I think the main problem is that the cost-center went through Japan so the japanese agents can be the only ones who can make changes to the tickets, and not AA in US. You might want to keep trying talking to the japanese agents (and if you're in tokyo itself, drop by their office).