I have purchased a builder flat on loan from SBI for 39 lakhs. Loan is for 20 years. As desired by SBI, I agreed to opt for property insurance. My property is under construction and I will get possession after 6 months. Early this year, SBI added Rs. 20,025 to my account as premium charges. How can I know that the calculation made by SBI is correct and they have not added undue amount?