False advertising(very disappointing)

I booked a flight with mango airlines considering their offered a special of 25%of edgars clubcard members. So I took advantage of the special amd booked the flight using my account details. However they did not give me the special as they advertises instead charged a R100 more,apparently which was taxes. So instead if paying the R825 less 25%. I paid R925. And booked it as I needed to book the flight urgently. I am very dissapointed considering it was my first time that I booked with mango airlines. Really disgusting for them to advertise falsely.