NO response from Rwandair

The ticket i booked could not be used last year due to COVID and they advised us that ticket is still valid. When I tried to reinstate the ticket i was told that Rwanda Air is not carrying passengers from South Africa. I then asked for the refund option. I was given a form to complete which i did and sent to them since then no response from them even after following up numerous times.... It has been almost 3 months now since then still no word... i tried their Cape town offices and they said there is nothing they can do.