Immediate response!!!!

On the 25th of December 2021 i was supposed to fly to Bulawayo from Johannesburg however i tested positive for COVID. I tried so hard to reach this company. It took three days to respond to me. On their website they stated that they are available even on public holidays. The number that is there doesnt go through. Eventually they rep**** they said i had flown. I was very upset eventually i had to change the date but they said i must pay the difference. The ticket intially was R4500 and i was asked to top up with R649. I am supposed to fly today and unfortunately i tested positive again. I have forwarded the documentation but no response on email or whatsapp. I even chose the option that i am flying in 24hrs but still no response . I would like an immediate response because i will be requesting a refund.