Qatar Airways *******

We booked a ticket from South Africa to Bangkok for 2 passengers to fly on the 22nd September and return on the 8th October. But we wanted to change it to the 6th October and they charged us the same amount that we paid for one ticket. We paid R8195.72 per person and they are charging us R7500 per person to change it. Have you ever ? I can fly to Bangkok for the 2nd time. So disappointed in Qatar Airways.