Jetstar ruined holiday

All documents were submitted 5 days prior to travel for pcr exemption. We then ring Jetstar 48 hrs before say will take note of this on file.
Get to airport no I wish they stop telling people that it’s not correct.
Lady rings Qantas to hurry process. We get told that we aren’t accepted to fly so they cancel our flights. Get home email comes through saying we were accepted however now we are canceled oh and 1.5 hrs after flight left.
We ring nothing they can do but we can purchase for tomorrow at 654 each and our return leg 580 basically paying $1200 each. Our original flights little under $300 each. Our voucher can be made into cash after we pay the new fees.
Absolutely disappointed with their service.
3 hours at airport countless hours on phone.

Have wait until 7-10 days to sort.

Indonesia-Denpasar (Bali)