Croma sales defective product.

As I knew Croma is a Authentic store from that expections I have purchased a mobile (one plus Nord 2T) from Newton Narkel Bagan Croma Store. After using 3days my mobiles battery started draining then I have visited the store for the replacement but they have neglected and ask for the servicing. Even the the coustomers service members was telling me,  if I purchase one and half lac product there won't be 2dasys guarantee, and insisting another member not to take my product on that day for the servicing. They didn't even bother to call after the services is done. I don't know what the hell they have done by the name  of servicing, the problem remains same. Croma started fraud business and making their coustomers fool by selling defective products. The worse coustomers service  in Newton Croma store . Very unprofessional they don't know the basic manners to talk with their coustomers. Unexpectedly very bad experience.