Assumptions apart and since you have posted that you do not wish to submit Aadhaar card:
Do you have copy of policy brochure, proposal form, enclosures filled, signed by you, acknowledgment of instrument of payment and written communications supplied to you by insurer?
Do any of these contain any clause on having Aadhar card/mandatory submission of Aadhaar Card?
Did you answer in Yes/NO fr having Aadhar card?
Or declinature to process the proposal form is verbal i.e. in person and/or by phone calls?
You have the option to write to supply you authenticated copies of all of the above and status of issuance of insurance policy…
Let the insurer write back to you. Thereafter you can communicate in writing. The customer and policyholder should transact in writing and keep copies of all docs.
Even if IT is not legal the staff follows the SoP issued by establishment and insurer has to adhere to guidelines issued by regulator IRDA.