AA refusing to reprotect after schedule change
F class award booked for two people:
YVR-LAX AS
LAX-SFO AA
SFO-HND JL
HND-HKG CX
HKG-DPS CX
Now, AS cancelled YVR-LAX flight, and automatically rebooked us YVR-SEA-LAX. There is a direct flight YVR-LAX on AA, at about the same time as the original YVR-LAX AS flight. This AA flight has one award seat, and we need two. I called AA, but they refused to open up the second seat saying that's AS who caused the schedule change, and they are not allowed to reprotect on AA. I called the second time, got a different agent, and exactly the same reply again.
So I am now stuck with an extra connection and Y prop flight YVR-SEA. Am I doing something wrong? I thought AA should open award space in case of schedule change?