Intex Mobile — Product could work well only for two months, product under warranty but company is denying it

Address:

Gurdaspur, Punjab

i bought aqua speed mobile on 19/03/2015 from BR ENTERPRISES City batala dist gurdaspur punjab. but after using it for just four months i found many problems in the phone.the biggest problem i am facing right now is its battery has stopped working. a 100% charged battery hardly works for half an hour. if someone calls on the phone it gets switched off. when i went toNATIONAL MOBILE CENTRE the official service centre of intex mobile in Batala city, they told me that battery needs to be replaced. my phone and battery is under the period of Warranty but the service centre owner is denying to replace the battery and trying to sell me the battery. owner of service centre has utterly rude behavior .please also explain how the battery of phone could resist for only four months, whereas the mobiles of other companies that i use are working in good condition even after two three years.when i sent a complaint i got only auto generated reply...