Discovery Vitality Empty Promises

I app**** for the Discovery Vitality refund for the Kulula flight tickets that was cancelled. I opened a Discovery bank account on 14 June. I app**** for the refund on 17 June. Since then I have received nothing but empty promises. I have spoken to Kelly (17 June), Lester (20 June), Danielle (23 June), Farhaana, (24 June), Shavonn (25 June), Bonani (1 July) and Tyrell (15 July). All of these consultants promised the refund will be done within 3 days. We haven't receive anything yet. So I have come to the conclusion that Discovery Vitality blatantly **** about the refund to their members. I do not know who else to contact or what to do to get the refund that was promised. The last reference number I received was: ***. Kulula booking reference: MB***E. Departure: 15 June. Arrival: 19 June. Must I sue Discovery for the refund? Let me know what action I must take to get the refund done. Vitality ***