Qantas recently changed a flight of mine, so that instead of having the five days I'd planned in my destination, I would have had 8 hours at the airport, which destroyed the purpose of the ticket. I was tempted to press the 'cancel' button online, but it seemed I might suffer financial consequences if I did that. So I called them. I got through after two hours; the person who answered was skilled and professional, but it still took her another half an hour to cancel the ticket. Shortly afterwards, I used Jetstar's chat function to enquire about a booking I'd made. The initial response came within a few minutes, and it was sorted out pretty easily. So yep, communicating with Jetstar was better by far.