Bad customer service

I booked and paid for 2 flight tickets with Mango to Durban from Lanseria International airport and my flight was supposed to be at 7:55 am. I arrived at the airport at 7:44 am and I was told that it is too late, they can move me to the 11:15 am flight on condition that I pay R1 021.50 extra or wait for the later flights that are cheaper. I decided to pay the extra R1 021.50 because I had an apointment with a car dealer in Durban and it is a Saturday they close at 14 pm. While waiting at the airport they made an announcement that the flight will be delayed by an hour, I stayed calm because an hour isn't that bad. An hour later they announced that the flight will be delayed by an extra 2 hours meaning that we will now leave at 14:15 pm, I was told that they can't help me with anything I should just wait. I was willing to fly with a different company. I asked for my R1 021.45 back because I wasn't going to be on the earlier flight anymore and I paid extra to leave early, to my surprise I was told to write an e-mail and wait for 48 hours for a response yet when I paid the money they wanted it on the spot. Chances are by the time I get to Durban the dealer will be closed meaning that I wasted my time and money to fly down to Durban. Mango is ***********, if there was a problem with the plane why wasn't there a back up plane, 3 hours delayed isn't a delay it is just pure incompetence. It is the last time I ever fly Mango. I was about to conclude my review but they have just announced that now the flight is delayed to 16pm, shock of my life I spent the whole day at the airport for nothing.