Well three calls later (first two went to off shore call centres and put me on hold for "approval" then hung up) I got it sorted. Third call was an Aussie (so HBA i guess) and fixed it for me with no issue (SFO-LAX-SYD). Also the first two said it was impossible to change because they can't book flights on AS for SFO-LAX. I had looked up availability on the QF site for SFO-LAX and they had "First Class" availability for the date i wanted and QF opened up a U seat for the date i wanted too. Amazingly, I got the eticket a few hours later. My ticket is a QF award ticket also.
They could do my SFO-LAX award because there was award availability. You basically have 0.01% chance to get QF to do anything if there's no award availability. Previously when they cancelled SFO-SYD, I did manage to convince them to put me on revenue J SFO-LAX on AA (got a good agent), but then AA cancelled the flights, so they put me on QF codeshare AA (revenue) with a 10hr connection at LAX, which i did not accept and then they put me on revenue AS with a shorter connection. Best bet is to pick a date with award availability from SFO-LAX, and they will put you on LAX-SYD even if there is no award availability. I actually wanted to travel earlier, so it worked out for me.
Also, i think the only reason they put me on revenue J was because they couldn't figure out how to book the award seats on AS (which were available), so i might of just got lucky. And once it was a revenue booking class, they could easily change to other revenue booking classes.