Cancelled flight with elderly parents

I am still waiting to pick up my parents who were supposed to arrive in Sydney at 5PM, their flight was cancelled, they were then put on a bus from Sunshine Coast to Brisbane and they are now on a flight from Brisbane to Sydney, they arrived at Sunshine Coast airport at 2pm, the flight was supposed to leave at 3.20pm. I rang to ask if they could provide a wheelchair for my mother at Sydney airport to get her to the arrivals pick up, but no because I hadn't pre-booked it then they wouldn't do it, I said I didn't realise my poor elderly parents would have been put on a bus and a plane and arrive home at 10pm at night, my mother will have trouble walking as she will be so tired, but no they can't help me. On top of that the person from Jetstar at first kept saying oh no they are on the plane already and I said no they are not my dad just texted me to say they were on the bus, I said to her what time is the plane leaving from Brisbane and she said 8.35pm and I said how can they be on a plane it is only 6.30pm now, she just didn't know what she was doing and didn't care. If anything happens to my parents I won't forgive them.