Universal Sompo — Mediclaim Rejection

My Wife had viral fever back in June.
As she have visited the clinic and took medication for 3 days.
But medicine couldn't do any better and her condition got worse even more.
As remedy doctor whom she was consulting they said to get admit and have some tests, injections, glucose etc.
I have admitted her by doctor's suggestion. And her health improved after.
Now I have filed for Mediclaim to my provider Universal Sompo.
I have waited 3 months for any reply and after so many efforts they rejected it.
Reasons given were "She didn't needed to admit in hospital it could be better by just medication "
I have submitted proper paperwork as they asked. Doctor's prescription and recommendation letter after this issue was created with Mediclaim Provider.
Now I have contacted my agent who sold me mediclaim who tells me to do FIR or Consumer Complain as he cannot do anything.
Show me a proper way or suggestion.