I've encountered poor service approx 3 years ago & the lack of concern from their head office was the icing on the cake for me. Approx 100 passengers were left to fend for themselves when our flight was cancelled between Toronto & Detroit at Pearson.In short, approx 1 hour from scheduled departure a delay was announced;people started questioning ground staff at the gate(pushy americans,I thought-silly me I realized in hindsight);I opted to approach another AC employee who emerged to explain I needed to make the flight to be able to connect from Detroit the next morning back to Australia;I'd be updated I was told;shift changes started happening;news now only coming from one staffer that the flight was cancelled-no other flights there for the day;no one else coming down to "sort this out" we were told & with some relunctance we were given boarding cards for a Northwest flight in another terminal/locate our checked bags/& check ourselves in less than an hour to do so.The luck ones who pushed seemed to have made the flight but I was greatful I wasn't travelling with my wife and two kids.Look in the big scheme of things,if this is the worst that happens to me I'm leading a very fortunate life. But,one the ground staff didn't care/have training to cope and secondly,head office replied afterwards to my concern with "we value your feedback" email reponse.I heard nothing further. Sorry,passing buck to me. I won't trust AC when next planning the journey between Australia and Canada.