Soft drinks sold at a price much above mrp

Location/place: Maharashtra

Name of company/service: Softdrink Vendors

In maharastra particularly in the nagpur region i have found that the softdrinks vendor are charging Rs 3-5 over the MRP on the pretext of cooling the coldrink . Say is the 200ml coldrink which is priced Rs 8 is being sold for Rs 4 . The extra amount is taken as cooling charges kindly look into the matter