52 % increase in premium

I am on the Blue door option with Fedhealth and in 2018 my monthly income increased by 17% which I know is a big increase so this year I automatically fell into a higher income bracket. I did not expect my medical aid premium to increase by 52 %, this is simply ridiculous, I can't see how the medical board could allow such a huge increase on a low income based medical aid. I hope somebody will look into this for me and reconsider this increase amount as I am now not able to afford this medical aid. I have always been very happy with the service I receive and the claims that they have always paid timorously. Kind regards M. Ribeiro