over priced flight leads to important function being missed

Booked a flight with Kulula for today 13/12/17 to leave 18:30. I paid more for this flight due to being in need of reaching Durban for an important gathering/function. Now i am at the airport, being told that my flight will be delayed till 19:30. it was a hard pill to swallow, now they announce that my flight will only depart at 20:30, which is ridiculous. i could've taken a later flight for cheaper or even tomorrow. now I'm stuck here, all that money spent for nothing. Absolutely ridiculous service from Kulula. if Kulula does not believe me regarding my important function, they are more then welcome to contact me for proof.