Truly terrible service from Kulula

I took Friday afternoon off work to fly down to Cape Town to attend an old friend's reunion. I arrived at the airport at 14h00 for my 15h25 flight, only to learn that it had been delayed to 16h10. I waited until 15h30, and then went to the boarding gate. The staff told me the aircraft had not yet arrived and were unable to tell me when the flight would be boarding. I went to the Slow lounge. I came back 20 minutes later, at 15h50: nothing had changed. At 16h10, I came back again, no one was boarding yet. I returned to the Slow lounge. I returned at 16h30. The staff said flight had closed 1 minute ago. Throughout this entire period teh boarding information screen indicated "flight delayed", not "flight boarding". Anthony Daniels, the Kulula ticket supervisor, said the best they can do is give me a ticket for the 19h45 flight (or, I could pay another R2500 to fly down on BA an hour earlier). I have wasted 4 hours of what was supposed to be a great weekend with friends. I will arrive at my friends' house at 23h00 on Friday, instead of 18h20 as planned. My family and I will never fly Kulula again. Incredibly disappointing experience.