Sony — Non covering of warranty

I had purchased a digital camera of sony make on[protected] from authorized sales outlet of Sony i.e. Parikh Sales , City Center, Dhanbad. First of all they do not given me bill when asked only challan issued. Now camera is not functioning. when contacted i have been informed that battery is not functioning and battery does not cover any warranty. If a battery fully damaged withing 3 months company sould liable or not