Atrocious service by Kulula

This is the second time within 12 months flying with Kulula and the second time our booking is a total mess. We were booked to fly from Johannesburg on 21 Sept 2019 at 08:10 arriving at ORTambo airport at 06:00 just to learn we were taken off the flight due to aircraft change and this is exactly what happened in June 2018. The attendant at check is so ill-mannered. Please don’t book through Kulula as your flights are not guaranteed even though you have paid and pre-booked your seats. They had the odacity to tell us we will be transported by car to Lanseria. If we wanted to fly from Lanseria we would have booked via Lanseria.