FLYSAFAIR REEPED ME OFF

I booked the return flight from Capetown to DBN,i booked the flight before i went to capetown,so while i was in capetown due to circumstances i had to reschedule the flight back to DBN as i was doing that online it showed that the flight i rescheduled to was cheaper than the previous one i booked so i will be refunded,but i ddnt get no refund i emailed customer care,got response from the agent stating that their new law is that i dont get refund if i rescheduled to a cheaper flight,well but on my side it showed that i was due for a refund Also later when i was in my bank app it showed that flysafair deducted a further R1400 from my credit card the same date i rescheduled my flight ,i'v been emailing them to get some clarification but i get no joy from their agents