Warning, travel booking through Discovery

I am a new member of Discovery Viality and Discovery Bank, which I joined for the travel discounts. I made my first booking through the APP, which seemed to work so well, until I needed to change my flight. My booking is through Safair, and they have messages all over the helpdesk saying they can't change bookings for Safair and a few other airlines. You have to contact the airline. They can help with the change, but you then loose your discount on the flights! So, to move my flight to another day, the new flight is over R1000 cheaper than the one I booked, but I would need to pay in R1600 pp to change the booking!!! There is a MAJOR flaw in this booking system, and I am so disappointed. Also no warning of this when you make a booking, which is completely unacceptable.