SAFAIR "LITE"" AIRTICKET TRUTH DID YOU KNOW???

So we had booked a flight a ticket through Safair for my nephew. Due to religious fasts we needed to change the flight dates. When we accessed the Safair Online Portal we experienced R300.00 being charged and a Voucher being issued for R169.00. We then thought this was odd and called the Call Centre and spoke to an agent named Dumisani who refused to give us his surname, not to mention that you could barely hear him. He then advised that nothing can be done as R300.00 was charged to make a change as it was a "LITE" ticket that was purchased. We then also requested a copy of the conversation. He further advised that nothing can be done. We find this utterly ridiculous as R300.00 to change flights is alot and practically losing the entire "LITE" ticket purchased. What is the R300.00 fee charge for? When the flight is still many days ahead?????????????????Wont someone else then take over that seat for another "LITE" fare or so???????? Another R469.00 then to Safair???