Kulula's customer service call centre is closed

We booked tickets to fly to CT in April 2020 for the Two Oceans Marathon with Kulula on a BA flight. Covid happened and the event was cancelled. We banked our tickets and sent an email confirming the bank. We received no response. We have been trying since February 2021 to get Kulula to respond to our queries but to no avail. We have received automated responses promising to resolve all bank queries within 6-8 weeks. We are still waiting 18months later. Their call centres do not answer any calls even after you are put on hold for 30minutes. BA referred us to Kulula and Kulula referred us to BA.