Nandini — Quality of Milk

I am from Kaggadasapura, and in recently, we noticed that the Nandini Milk vendor Suresh is occuationaly serving the bad quality Nandini milk, which can not be consumed either due to bad odor [bleaching powder] or milk it self is spoiled. So checking the milk vendor, Suresh, he indicates that he don't have any control over the quality of milk, which he getting from Nandini. So wanted to check if any remedy for such issues or who is the concerned person for this. Thanks, Pradeep [Kaggadaspura]