Oriental Insurance Company — i am complaining about a company not approve a full insurance claim amount

Address:

Oriental House,A-25/27,Asaf ali Road,New Delhi., New Delhi, Delhi, 110002

Dear sir,
I informed u that the oriental insurance co. Ltd, is not approved a full claim amount of our health insurnce. It's detail as below:
Patient name : neetaben
Policy holder: dashrathbhai joitaram patel
Policy no.144000/48/2019/8402
Provisional diagnosis:unilateral primary osteoarthritis, left knee
Date of admission: 6 jan 2019
Summary of authorisation:
Total estimate:rs. 255093
Initial amount authorised:rs.234600
Revised amount authorised:rs.190493
Dedction:rs. 64600
Final amount authorised:rs.190493