Unexpected Travel Marathon

I was flying Sydney to Melbourne, Melbourne to Honolulu on Friday 29th Jan. 2016
Got to Sydney airport early and they said that my flight to Melbourne was delayed and I would miss my flight to Honolulu, however they could get me on an earlier flight... fine, good I'm on my way!!

Get to Melbourne, collect luggage transfer to International and look on the board to see that the flight is CANCELLED!!!!
NOOOO. I was on my way back to Canada with an 18 hour stop in Honolulu. Had booked a hotel room and transportation to and from the airport.
Very long story, 3 agents later and total runaround. They initially told me that the flight had been cancelled the night before, and that because I booked through a 3rd party and not direct, then they were off the hook!! Offered me a flight out the next day! I said no way, they said take it up with your travel insurance. I was relentless, and fuming, and because I am of a certain age, I pulled the "I'm going to have a heart attack with all the stress"!!!!!
The next agent said that it had been cancelled that morning. My question was who is telling the truth? Also The checkin desk in Sydney should not have put me on the flight. I had also checked, the night before, the flight status on Jetstar web site and it did not say anything.

Found me the last seat on Qantas, Sydney to Honolulu, leaving at 10;30pm Had to get back to Sydney, back to domestic with luggage. flight delayed, its OK as I had a 5 hour wait in Sydney. Again had to transfer to international at Sydney. 12 hours later and I am still in Sydney!!!
44 hours later I got home. I had paid for meals, flight entertainment and for seat selection and baggage, none of which I received. I am not going to complain as they only give you a voucher which you have to use in 3 months, ha, they are kidding.

United States-Honolulu