No refund from Kulula total disregard for customers, where is my refund???

Tickets booked March 2020 to travel to CT on 10th April 2020 and return 13th April 2020. Due to Covid this did not happen. Issued with travel voucher for myself, my husband and 2 grandsons. Come December not able to use the vouchers to fly. January 21 told to set up a Travel Bank account and money from vouchers would be refunded mid January. Mid January received an email asking for booking codes, flight numbers dates of flights passengers names. All sent now at 2nd February nothing. Not even the decency to reply to my emails. We are pensioners so R26000.00 is not something we can throw away. Does anyone know how to get Kulula to do the right thing for their customers? I would greatly appreciate how to get them to respond.