Terrible service !!!

My flight to Perth from Johannesburg, the departure time was changed from 19h00 to 22h00. I was informed of this three days before. This meant I missed my connection to Brisbane. They put me on a flight, that meant a 9hr wait in Perth, but after much stress & discussion, I was placed on an earlier flight, eventually arriving in Brisbane over 4hrs late, but minus my luggage. After contacting the company care line, I was told the flight delay was caused by a mechanical problem with the aircraft in Joburg, & then they blamed the weather. When I tried to checking in for my return flight from Brisbane to Perth, my booking had disappeared, again causing major stress, while trying to get it reinstated. Terrible service all round, including the cabin staff.