When RBI Lowers the interest the Interest rates of Loans must also come down automatically ,The interest rate one avails must be linked to the prime interest rate i.e Prime +- X% and then this information on the Loan must be available online where you can track you amount you have paid , principal,interest etc. Banks have failed to  inform customers of the fluctuations on interest rate and they must be hold accountable for not doing so , since lockdown if banks havent done so they my pay back the difference