advice for the following situation

I booked a flight using points from MEL-LHR in business on QF29 however Qantas canceled the flight on that date and changed my flight to the earlier Qantas flight 9, however I have an appointment for the day and thus thats why I choose the QF29 departure as it leaves at midnight giving me plenty of time to get the airport.

Would Qantas be willing to rebook on the Cathay flight that leaves at 01:05am via HKG, or even the following day on Qantas

Searching the Qantas website there is no actual award availability on the following day in business, would Qantas create a seat for this day for me I am Qantas Platinum if that would help.

I thought I would ask here if anyone has had a similar situation and what the result was before calling Qantas to see what they could do for me

any advice greatly appreciated