Bajaj Finance — Loan with fake commitments turns to huge debt on me

I have taken loan of Rs. 240000 from Bajaj finance that is called flexi loan in 2019. The rate of interest promised by the Bajaj finance executive was 9.00 percent per annum. On approval it was 19 percent per annum. I was not aware of it at 1st. But one day when I checked the statement. I was shocked by this. And yet they only charging me interest since last two years. The principal amount is still pending in full. The whole debt is for 7 years that will count to about Rs. 500000/-, double the amount I received. This is a whole big financial burden on me. So your good self is requested to take necessary action as they have hidden real terms and conditions from me. The loan was approved with an OTP only. I have not signed any loan agreement.