Uncredited Travel Bank

Several of my booked and paid for 2020 Kulula flights were cancelled due to the COVID lock-down which commenced in March 2020. Kulula made the undertaking, as published on their website, to credit the value of these flights to a persons Travel Bank account within 6 to 8 weeks of the individual requesting this to be done. I have sent several emails in follow up to my request, tried to call the call center - but this had proved to be futile as the calls are often dropped or simply not answered. To date no correspondence has been received from Kulula in this regard. Further to this, the time allocated by Kulula to effect these travel bank credits and to use the funds accumulated, is now running out.