I am about to take AC16 from HKG to YYZ next week. When I bought the ticket in Jul, the departure time was 13:55. In Aug, AC changed the departure to 13:20 and I accepted the change. I just found out yesterday the departure is now changed to 10:25. Is it possible to ask for a refund or change of date without paying the fare difference because the new departure time is now more than 3 hours from the original time when I purchased the ticket?