Aside from the medical aspects which have been covered very well above. There is the one thing you can do in the face of doing something against your wishes. You can find another company to work for.
Unfortunatly those of us on the lower end of the food chain work FOR those companies we dont OWN them. Working for, means subserviant to.
They have reasons for their actions probably based on monetary concerns. Like when you get Malaria and they have to pay for your medical and loss of work. Preventing this problem is called Fiscal Responsibility. A small investment to save a big expenditure.
You can probably find an Attorney sitting on the fence who will also take your money up front, stir some sh1t and leave you hanging.
If you want to work for the company, I would suggest some research on your own to see if you are making a wise choice. If you still have strong beliefs, maybe it is time to move on..
Good Luck. Keep flying........till your 57
Come to think of it. Im still flying and Im 61, pay is good too. What am I doing right.