You are obviously angry at the airline at the moment and I feel for you, but since this happened yesterday, I have spoken with QF 2 times, once yesterday and once today. It took me approx 5 mins of random redials to get through (while eating breakfast), then a few seconds to be answered and solution found (admittedly I did offer the solution as the poor CS agent must have been receiving some cough today!). The new booking arrived by email within an hour. A change of flights from scheduled tonight MEL departure has me now via CBR using QF Link. I realise that this is a little different than going stateside (from which I returned on Thursday) but personally, for jetlag reasons alone, and for something as important as an award ceremony, I would have given myself at least a day's grace on arrival.
QF look after their frequent flyers very well - I can (and many others here) can contest to that.
As I said, I am sorry about you missing the presentations, it must really cut deep, but if there's >24 hours till it happens, SQ can get you there ex PER via TPE. I would be moving hell and highwater to be there if I was in the position you say.