how can we ask for a decrease in interest rate of homeloan from Pvt bank, when RBI reduce the interest rate?

we have taken a home loan( not fixed) from HDFC bank, as few days ago when RBI reduced interest rate they dont relief us and not answering our question properly, so how we can approach them to reduce our interest rate , now as the interest rates can be going down, i want to ask how we can facilate us and go from a higher interest rate to lower one? kindly suggest?