Flight canceled then delayed then stuffed up seating

I have always taken delays of a few hours on the chin as Jetstar is a budget airline until now...so fight home from Bali to Melbourne at 11.15 pm canceled ongoing flight to Tasmania next morning we had a few hours layover obviously can't make that one now with a days notice flight from Bali rescheduled for 1.30 pm the next day pay for a extra nights accommodation the 1.30pm flight delayed until 3.30pm board the plane and my daughter realised they stuffed up her seat as we paid more for 3 extra leg room seats they tried to give her seat to another passenger i thought no worries i have the flight details on my mobile starting seat number and proof of purchase all good but no 2 staff tried to convince me otherwise 15 mins later a superior said let her have the seat .... announcement on the plane just before landing see a Jetstar team member on landing if you have a ongoing flight ..... OK no team members around on landing try domestic terminal no one for a couple of hours and they can't help so we got to spend the night in the terminal building with no seating until our 8.50 am flight home to tasmania the next morning Jetstar did refund a portion of hotel costs 2 weeks later after making a claim and sending proof of purchase in and some food vouchers supplied in airport but simply not good enough horrible end to our Holliday

International
Indonesia-Denpasar (Bali)
Australia-Launceston