We were on the SFO-SYD #863 July 13th that was cancelled. Because of other cancellations earlier that week the best the Agent could do was SFO-LAX-SYD on the 15th in coach.
He was adamant that because I had "upgraded" a coach ticket I could not be re-booked in business. I could not be rebooked on another airline. Multiple calls to the 1K Desk finally secured C on the flight to AKL on Friday, and then on to SYD.

I was under the impression that once I had a Business class ticket I was entitled to another Business class seat, even if on another airline? In this instance I am very happy we got two seats out to SYD via AKL on the Friday, and there was very little capacity on any other airline, any other routing.

I would like to know what options I have if this happens again?