Refund on my flights

I made a flight booking back in Feb 2020, then Kulula was grounded for lockdown, and I haven't had the need to travel since then. Now that I called in because I would like to redeem that flight voucher I'm informed by the consultant Tazz that the period to redeem all lockdown vouchers has expired, mind you I was not sent any communication regarding this expiry date via sms or e-mail the consultant told me that it was on the social media and website and those are not the direct methods of communication to reach all the relevant clients including myself as I am not on social media and I only visit the kulula website if I need to book a flight, kulula sends adverti*****ts on e-mail but when it is time to notify me as a client on crucial information they choose social media and not e-mail because ??? I find it extremely ********* that you choose to keep my money as an individual for reasons that you could not perform your services, this should not be at my expense. I would like what is due back to me without excuses or a laundry list of excuses as to why I cannot be paid out what is duly mine