However, the people on the AC lost baggage phone number are not straightforward. They say they have information but won't provide it, or they say they don't have information, when it is information they should have.
They have been completely useless every time I have had to deal with them.
However, my bags have eventually been located and delivered.
(And even then, the people on the phone line and the baggage tracking website show the bag as still tracking in progress.)
Even if it was not AC that lost the bag(s), the last carrier on the itinerary is the one responsible to the passenger. In my most complicated case, LH misplaced the bag but it is still AC that "lost" the bag as far as customer service responsibility goes.
Joe Hou, I am sorry this happened to you, and I hope your bags do arrive soon.