One Qantas problem is that despite a hefty advertising budget they still can't get customers to spell their name correctly.
While it is unfortunate that you've had to deal with flight changes it seems that Qantas have offered the best alternatives possible given the situation, however due to your constraints you're unable to take them. Assume you could get compensation if downgraded?
I was due to take my first flight on the A380 this week (to LAX). This is my third attempt to get on that thing yet something always changes the Qantas schedule! I'm frustrated but know it's not something I can complain about.