PAY BACK MY MONEY!!!

I Booked and Paid for a return flight (CPT-JHB) for 4 adults and 2 Infants on the 8th of April 2020. The event that we were going to attend has been cancelled and will no longer take place. I do not wish to travel and requested a full refund. The Kulula call centre agent advised me that I may only use my tickets from 11 Jan 2021 - End Nov 2021 and that they do not pay out any refunds. How can you ***** MY MONEY AND TELL ME WHEN I MAY AND MAY NOT FLY. I WANT A FULL REFUND AND WILL NEVER FLY WITH KULULA AGAIN!!