Madical incapacity

Good day i was recently diagnosed with prostate enlargement then i went for brachytherapy in 2020 after that i went back to work with the side effects from that therapy but this year the side got worse to such extent that I was unable to perform my duties and the company docter and my private doctor gave me permanent madical incapacity but now the insurance people without even seeking second opinion from a different docter decline my claim according to them i am not sick so they expect me to work where as I don't reach health standards of the company