Well they just did...on the first call! I couldn't convince CA to do it.
Just waiting for CA to come to the party now as promised...
So closing this one out...I hope!
Miraculously US waitlisted the segment. I assumed it had cleared as at first I saw the 2 segments on my US itin, the one Air China originally moved me to, and the second the one US WL'ed. Then only the WL'ed one was shown. Online with US you don't see 'Confirmed' or 'Waitlisted'...only 'Active'. So after the duplicate segment disappeared, I called up to try and get the ticket reissued...the 'Accept Changes' button was not shown online.
At that point they told me they couldn't ticket...they didn't give a clear reason why but in reality I think simply the waitlist hadn't cleared yet. Instead they told me 'Air China is no longer a partner'...um, yes it is! I was told they had a supervisor there and let's try and rebook the whole thing on OneWorld...bearing in mind this is a GUM trip I said...NO, LEAVE IT ALONE!
I tried calling the Air China Aus 1-800 number...they were hopeless, sorry there are no seats on the 9th or the 11th...tough! So I called back a number from Melbourne that I had a missed call from an earlier day. The guy who I spoke to was super helpful. He explained he'd been checking on it regularly, that the waitlist hadn't cleared as the relevant person in Beijing wasn't in the office but he was going to follow up and let me know. I got an email later that day saying they'd cleared the waitlist.
Sure enough, when I logged onto my booking on usairways.com the 'Accept Changes' button was now shown. Against my better judgement, and sick of speaking to US agents, I decided to click the button. The spinning US flags appeared, but never went away, I left it for several minutes. I opened up my reservation in another tab and all looked well, no longer a message that the itin changed, however I was immediately suspicious that the ticket numbers had not changed. Checking the ticket on the Travelsky system today I could see that the ticket details were not passed to Air China. I tried to call US a few times today and each time waited on hold for about 30 minutes before giving up. Finally on the drive home from work I called again and got through quickly. Explained the situation to a super nervous sounding agent who really appeared to have no clue what she was doing...she kept saying there were no seats to give me, even though I knew they were 'HK' - waitlist confirmed but not ticketed. What followed was quite bizarre, I think she got the manual out and essentially keyed lots of stuff in manually, as she did it she whispered every keystroke out loud...it was very odd! It sounded to me like she was doing some kind of long sell type thing. Eventually she told me new tickets were issued. Finally, plugging those new ticket numbers I can pull up the flight details in Travelsky!
I really can't speak highly enough of the CA service on the Melbourne email address.
So it looks like the GUM trip is definitely a go...no more schedule changes please!