Group Booking ***** up of note over charge

WOW where do I even start. Ridicules!!!!!!!!! My wife booked 12 tickets from or Thambo to King Shaka as a group booking. She wanted to change the flights times, Phoned the group booking department spoke to a lady by the name of Pamela. She then continued with the call and this lady said that the amount is R26110.66 and my wife said she already paid R24683.00 for the tickets, Pamela then stated the difference of R1426.00 and my wife asked how do we pay the R1426.00 and Pamela stated on the internet. My Wife went online and saw That we had to pay an additional R26110.66 for the 12 tickets. Witch we already paid R24683.00 this accumulates to a charge of R50793.66 for a group of 12 people to King Shaka from Or Thambo. I phoned and spoke to them my self requesting the audio that was recorded and still was said that I had to pay the R26110.66 for the flight to be booked. In my opinion that I read in the T&C it would have been R300.00 per ticket change and i understand that their are fees involved but this is bad we basically paying for 24 people but only 12 are allowed to fly (that was not stated to my wife on the call at all) now all of a sudden I must lose my R24683.00 that I have already paid and can not receive a refund on. This is ******* if you ask me, in the recording my wife stated that she is not very clear on how things work for its her first time booking flight as I always do it for her. I even asked them to just give us the old times back and they said they cant we need to pay the outstanding amount. We travel a lot to Cape Town and use FlySafair allot but if this is the way you treat a customer and The Rate that I was charged I will not in my life book another flight with this airline.