Bajaj Finserv — Falsely booked and insurance without our Knowledge

My parents had got a call from this company regarding the Health insurance and due to language problem my parents had disconnected the call and later after few days we got a msg stating the Insurance is booked on the personal loan account which we have from the Bajaj finserve.
and we tried to contact them and even wrote a letter regarding that and aoolied for the refund. they stated that within 5 days the refund will come and the loan amount which is around 15000 will be reduced as it is falsely booked by some agent.
later today my father had visited and they said the mannger cant meet today and asked him to come back on monday so i had called him and when i had called he was too harsh and not ready to talk at all so i warned him i am willing to give a complaint against these people who took our money without our approval and still harsh and not responding properly with us.