taking more money than MRP on various commodities by giving false and nonsense reasons

Almost every retailer in my town are taking more money than the fixed MRP on commodities like cold drinks, package milk, water, etc. I far as i am concerned about the trade companies fix the MRP so that the retailer could gain the profit but still these retailers are taking more money and beign rude with the customers if they are objected by them. Some of the retailers are SHARMA CONFECTIONERY, SHRI BANKEY BIHARI and many others. Plz do something in this context.
Thanking you