Both ways - put out

Was supposed to fly Direct to Honolulu from Melbourne on 5/05/19. On the Wednesday was SMS flight cancelled but you have been upgraded to another direct flight flying out from Sydney.....But I live in Melbourne. Get to Sydney and our entire plane of passengers become a void to Jetstar-we were ignored and even walked away from. Waited together like cattle to the slaughter for three hours before some one from Jetstar made a move but even then the desk person for us was just rude. Stating that the flight was all booked up, we had to accept what they had given us and if we were unhappy with the seating then we would go to the end of the queue for the last placement if any. Cattle class for 9 1/2 hours to Honolulu. We had pre booked and even selected our seats but - poof - that went up in a cloud of smoke. Then on the way back we weren't even seated together. Same rudeness given out to us at check in. The staff weren't even obliging or friendly or noticeably Australian speaking. At the end of each flight they insulted our injuries by advocating we were "VALUED CUSTOMERS" and look forward to our return business. LIKE - A - NEVER.