Discovery Vitality just not helping or just dont want too

We booked tickets to Miami USA through Kulula and BA cancelled our flight (covid) we then book again and again BA cancelled our flights (Covid). We have been pushed from pillar to post and told millions of stories. They keep on send us to BA and BA say that on Vitality can ask for our refund. Still to this day Vitality are messing us around. When you phone Vitality one person try's to help but never gets it right the others just don't know or keep passing you around. I am very sure there are loads of people with this same problem. All we want is our refund so we can rebook our holiday its not much to ask for.