🛑Help!!

I am a TCS employee.I was working in night shift but after few days my shift timings changed.Due to extreme weather and underlying health issues ,I fell sick in office few days back . After consulting my doctor I was advised to avoid sunlight . So I requested my supervisor to let me work in night shift but my request got denied. On a call with my HR ,TL and Delivery manager, hr agreed to look into it after verifying the documents by TCS doctor but she later on the same call refused. I was harrassed by my delivery manager by asking me to leave the organisation as soon as possible as he feels I'm of no use to this organisation. This is just an instance, there were multiple time I have been put down by my seniors.It is very difficult for me to work under these conditions. Due to extreme weather, I got sick several times . I'm not getting any help from the superiors. I have tried to contact my HR multiple times via mail and call but she has been totally ignoring me. I have been ignored by every higher authority of office that I have contacted. Kindly give you valuable opinions. Thank you.