Mango Airlines - Cancelled flights

We booked a ticket to Port Elizabeth on flight JE 541 (21 May 2021- reference number TVCCYZ) for my son at a cost of R 649. Well knowing that Mango at that time experienced financial restrictions with a great possibility of flights being cancelled, which the general public were NOT aware of, bookings and payment were accepted. When this problem was made public we immediately sent them an e-mail (18 May 2021) and also attempted to contact Mango by telephone, to no avail. All other attempts to contact them also failed. On 7 June 2021 we again attempted to contact them, backed up by a further e-mail (7 June 2021) and further unanswered telephone calls, to request a refund of our money. In my opinion the situation is unacceptable and they owe me money. As of today we have received absolutely no response and I hold them responsible for the refund.