I was a fan, but not anymore

Hi I have always been a fan of Kulula but not today. I booked a flight before COVID19 happened before we went into lockdown on March 2020 for 07 May 2020. I was told that i cannot refund the ticket but then i can request a travel voucher which i did but it was not the full amount i paid for the ticket? I was credited R500 instead R1200. This is unacceptable - should a proper procedure not be put in place?