Bad service, and would like my refund!!!!

i bought three tickets online and made a mistake with one of the tickets on the departure airport. i literally called fastjet and spoke to the supervisor Cynthia whom she refused to give me her surname as they are not allowed to gicve clients their details.

Am asking to change departure details, now they asking me to pay R1200 for name change plus 15usd, but i initially bough this ticket for 1400r HOW BEST DO I GO ABOUT THIS, she wont allow me again to do name change on this tickets, am disappointed as i always travel with them.