Charging more amount than , MRP

I purchased a Coca-Cola bottle from G Biryani, priced at Rs. 35 as printed on the bottle. However, I was charged Rs. 40 for it. When I questioned the extra amount, I was told that the additional charge was for chilling the bottle and to cover electricity costs, even though the same product is available elsewhere at the printed price of Rs. 35. I do not think it is right to charge more than the printed price on the product for chilling or electricity reasons. I request that G Biryani be directed to refund the excess amount charged to me and to stop overcharging customers beyond the printed price of products.