Why not today we rip you off?

I booked a mango flight for my wife and daughter on the 22nd Feb for R450 each from DBN-Lanseria for the date 9 March 2016, however a week before the flight there were unforseen circumstances which arose while my wife was in DBN. Therefore I had to change the flight to a weekend. When I went to the mango website as normal I seen a price of R432 for 12 March 2016 from DBN-ORT which I did not mind changing the airport as I was dependent on prices and noted that I only had to pay the R280 change of ticket fee. However, when I logged in to change the tickets it changed to R614 and not the original R432. I went back to the normal mango page and it still showed R432. Mango is a big ******* when it comes to changing tickets and not being fair to charge the normal prices as per normal website. Why not NEVER AGAIN MANGO?