I'm interested to know who promised to call you back? Was this as a result of an email exchange or on the phone?
Either way if you were expecting a return call from QF I agree it is poor to have not done that within a reasonable time.
However I'm also, in general, in agreement with the general feeling here - SG is not too hard to retain (and before May you could well do a trip or something to get some SC's... if you're much closer to 600 that could potentially sway QF - but you didn't indicate how many you currently have).
It takes two to tango, and on the bass of what you've posted you're asking for things but not really backing it up apart from the promise of spend on the transpac flights (and yes 4xY+ is a fair spend) - but then what further? Also good luck with VA in your quest. Have you considered the current NZ sale which has J to LAX at the $5400 p.p. type level which seems in line with your projected spend (but the dates could be the problem, given you say June - or US Summer, which is a peak time).
And that's the last point. YOu're not looking to travel at a shoulder or low season, but a peak season. Chances of all those upgrades as a Gold will be tough. Sure not impossible by any means, but difficult given the 4 pax (I did like the idea to split bookings as above should this be attempted so at least say a parent and a child could sit in the good seats).
If it were me I'd contact QF again and remind them that you had been expecting a return call and had not heard anything and to politely enquire on that - ie; remind them of their CS failure *may* see some flexibility but honestly I don't the rules will be bent for this sort of thing.
Why not try to get to 600 SC's ? If you've already done at least 1 US trip in youc current membership year you'd have, I'd guestimate, >300 SC's? How far off 600 are you? You have time to make them up
