roi

I have a home loan with HDFC. It started at 7.5% ROI, but gradually increased to 9.15% now. When I visit HDFC website, I see their HL starts from 8.5%. I have a CIBIL score of 799. Can I request them to decrease my ROI to 8.5% based on my CIBIL score? Is this possible? If so, who do I mail?