Not making full payment as hospital bill

My Wife Sheela Chandravanshi was admitted to Apollo Chennai for the treatment of her severe back pain on 11.11.2020 & after medical examinations , it has been decided to carry out surgery of the disc as treatment.
I am working in Dalmia cement Meghalaya & have group medical insurance coverage of Rs 6 lacs , so I started the treatment using cashless facility by duly providing information to insurance company.
The surgery of fusion was taken place in her 2 discs L3-L4 & L4 & L5 & also IVC filter done. Hospital informed me regarding expenses around Rs. 7 lacs & I was assured that Rs 6 lacs will be paid by Insurance company & remaining one lac I will manage on my own.
On day of discharge, Star health insurance refused to pay Rs 6 lacs as coverage instead they reimburse only Rs 3 lacs, saying that One disc extrusion will be paid only 3 lacs. I was shocked & in deep trouble to pay the bills, but any how I manage to pay rest of the money by the help of my friend`s support.
Later I requested Star Insurance to reimburse remaining Rs 3 Lacs by justification that surgery has been carried out for 2 discs. On their requirements I sent all the required original documents for validation. After sending all the documents & followups finally they rejected my request on 21st Jan 2020, saying that As per sub-limit incorporated for major surgery (Extruded Disc) the maximum amount payable for treatment is Rs.3,00,000/- and we have settled the same towards hospitalization expenses in cashless facility for the above claim.
Above logic is not applicable if not applicable as Rs 3 lacs shall be paid for 1 Disc operation, whereas surgery of my wife was for 2 disc & also for IVC filter , which cost nearly 1 lacs Rs.

Sir, medical insurance is matter of trust & customers are assured that at-least insurance coverage money will be paid in case of any medical emergency, but by harassing the clients, they are creating atmosphere of mistrust & betrayal .
Sir, I request to kindly do the justice, so I can get at-least the coverage amount which is justified & my rights, at the earliest.
I am submitting all the desired documents for perusal please. I am confident that you will consider my case & resolve this with empathy.

Thanking you Sir,

Rajesh Chandravanshi
DCBL Meghalaya
claim no. CLI/2020/161200/0635363
Policy no.:P/161200/01/2019/012323