You might try calling the airline yourself and perhaps asking for a supervisor if the agent says no. And if it's worth the trouble, you can also try calling a globally-remote JAL office (e.g. Tokyo) - no one has mentioned that JAL is heavy into point-of-sale availability, but that may be the case.

It would be disappointing to learn that JAL controls its capacity so tightly that A seats are never available. Please update your thread with any progress or lack thereof.