Will not refund me despite a travel ban

Made a booking to Mauritius on 1st of march before any covid19 had affected south africa or Mauritius. After the presidents 1st address i enquired about cancelling and getting a refund. I was informed that no refund is possible because there is no travel ban in place. About a week later after a travel ban to Mauritius came into place i was told that policy was changed and no refund was available . I had to either take a voucher and pay a difference later if prices changed or pay cancellation fees. Also of note is that i never recieved any travel vouchers at all so was unable to take out my own travel insurance. I got no joy from the travel agent that i booked through and recieved the same response from the customer care center. Very very disappointed and will not use or recommend flight centre again.