Foreclosure charges on overdraft

I have a Bajaj Finserv overdraft account which is advertised and sold as a flexi loan. I was informed that based on my credit score the total limit I have been approved for was ₹17 lakhs. I was not informed that I could have a reduced limit and that it would impact the foreclosure charges. I have paid off everything I drew down from that limit with the exception of ₹400. I am being told I have to pay 4-5% of the total credit limit, roughly ₹90,000. Foreclosure charges is meant to serve as a safeguard against loss of interest earned by the company. But in case of an OD where I simply do not utilize the balance, how can I be charged for a loss of interest? How can I dispute or avoid paying such a large sum for interest that would never have accrued?