Kulula taking advantage of the global pandemic

Kulula released a statement saying you can change your flights for no additional costs or cancel your flight for a full refund in the form of credits. I've been phoning to cancel my tickets (booked for the 19th of March) since Saturday the 14th. I've tried to cancel online and online it says that 'online cancellations are not permitted' and to please phone the same number that does not work. When trying to now rather change my flights, they want to charge me a full fare. I have got type 1 diabetes and my wife is pregnant. Kulula now forces us to either fly or lose our money. In the midst of a global pandemic, this is lying and taking advantage.