Was on AC8456 today from Montreal to Boston. I saw our load was very light. About an hour before boarding they cancelled out flight for "maintenance issue" so the girl at customer service said no compensation.

I then walked the terminal and saw our exact plane that was supposed to fly to Boston is now flying to Washington Dulles instead at 1:35pm. Doesn't seem like a maintenance issue to me.

Does anyone have a suggestion as to who I can complain to about this? Do you think it's even worth it?