Hi, so I booked myself onto a flight from YYZ to YVR and two weeks before departure, the flight doesn't exist on AC's website anymore. Calling AC is pointless as they're not picking up the phone. So I called Amex to see what was up; they said that particular flight was full. I later checked on Expertflyer and found that particular flight is half full at best.

My question is, why did AC pull the flight off it's website, why is Amex Travel telling me it's full booked, but Expert Flyer shows that it isn't full booked?