Qantas classic reward flight changes into Tokyo means I will miss a connection to Dubai - Any advice on what to do?

Hi all, I am after some advice please. I have rewards flights booked for early August. Melb – Tokyo (Narita) with JAL and then onto Dubai with Emirates. The two flights are on the one booking reference/ticket.
The JAL flights has been rescheduled for 18 hours later than the original time so I will no longer be able to make the Emirates flight. Both of these flights are for business class. I need to make this flight to be in Dubai on this date.
I have had a look at alternatives and all I can find from Australia to Narita, to make the Emirates flight, is a Jetstar flight (rewards seats) from Cairns. And I can’t find anything to Dubai on rewards seats going through Singapore, Bangkok, Sri Lanka or KL.
I have spoken to someone in the Qantas call centre in South Africa who wasn’t able to help me apart from offering to cancel the flight.
Any suggestions before I cancel my JAL flight out of Melbourne for a Jetstar flight out of Cairns?
All suggestions will be greatly appreciated. Thank you

Unfortunately I have the same sort of issue. We have reward bookings on JAL from Sydney to New York on 17th September. They canceled the New York flight and moved us to a flight that departs Tokyo 6 hours before we even land in Tokyo. I have contacted Qantas 3 times (because they never get back to me within the time period they say they will) who have only said that they are trying to contact JAL, they can’t see any other availability and that if I want I can get a refund.

The flights were ticketed but I’m not sure what responsibility they have when it comes to reward bookings.

How frustrating for you.
I have booked the Jetstar rewards seats but have yet to cancel the JAL seats. The JAL & Emirates flights are the on same ticket. After hearing some of the horror stories I am terrified that if I cancel the Melb - Tokyo leg the Emirates flights Tokyo to Dubai may end up cancelled as well.