This is bizarre! When you call ANA from Australia they have multiple dedicated 1800 (free) numbers you can reach them at, including a call centre in the Philippines for simple issues that picked up straight away for me. I wonder why they're so much more customer hostile in their own geography?
In retrospect I probably should have tried making a free VoIP call to their US 1800 number. Although I’m not sure if their US office is able to make changes to itineraries that originate from Japan (and vice versa).