A terrible situation
@Hutch0007 and I feel for you. However now is not the time to be debating what if and alternate scenarios. time for action.
A way I dealt with a couple of issues dealing with refunds was to get a Stat Dec done. you can do this with a Justice of the Peace which is a free service. Certainly this applies in NSW and QLD when I had my issues. Make sure you put in all the amounts that you are out of pocket. As well the screenshots etc that back up your case.
The effect of this in your case is to let Jetstar know you are very serious and likely to take things further. That should prompt them to make a realistic offer. If they don't play ball then suggest to them you are going down the tribunal pathway. That is going to be more expensive for them than your costs and if they are sensible,not a given I know, they will settle then.
I wish we could welcome you to AFF under more pleasant circumstances. All the best.