During college time, I opened a savings account in UCO Bank in which I have to maintain 2500 rupees. Now I am working and planning to close this account. Is there any benefit to retaining it, as I already have two accounts with another bank?

Hi
I purchased health insurance 3 months ago. Everything is covered by this insurance. However, 20 days prior, I consulted with the doctor as I was having stomach pain. After all the tests and CT Scan done, they found stones in my left kidney. And I need to remove that as soon as possible, as it's damaging my kidney. And now, after the operation is done, I contacted my insurance company to start the claim process.
Now the insurance provider is rejecting my claim. They told me it was an old health issue, and while purchasing the insurance, the company was not aware of the kidney stones issue.
Now please tell me what I should do. I have all the insurance papers, medical test reports, doctor’s prescriptions and consultation papers, original bills, and all the other proof.