score:8
At best you can ask for a refund but no compensation.
Let's look at the Qantas Conditions of Carriage
We will use our reasonable endeavours to operate in accordance with our published schedules. However, we do not guarantee the flight times and they do not form part of your contract of carriage with us.
If, due to circumstances within our control, after you buy your Ticket we make a significant change to the scheduled departure time of your flight or the flight is cancelled, we will:
rebook you on the next available flight (or combination of flights) on our services to your booked destination at no additional cost to you
[or]
alternatively, at your option, refund the applicable fare