Star Health and Allied Insurance - StarHealth did not pay full amount

I have a policy#P/******/**/****/****** on my Mother name. The policy was taken in **** and i have paid renewal fee * times on or before time always.
My mother had Gasto problems on Sunday **th June and was admitted in Sarvodaya Hospital Faridabad.
Initially company did not provide approval and i had to call them many times, sometimes they were so unprofessional that they put my call on hold for ** minutes after many follow ups they later provided the approval.
The doctor advised us to discharge from the hospital on **rd June and the total bill amount was ***** claimed by the hospital but the company refused to pay and said they will pay only *****/- which was **** less then the claimed amount.
While i call the star health and asked the reason they said Hospital was charging wrong and hospital says he is right.and in the last i had to pay hospital the remaining amount.
It was really surprised that the star health insurance for whom i was paying premium for * years denied and that also with out proper reason.