Micromax — battery

Address:

Kolhapur, Maharashtra

I have micromax canvas Knight (A350) having totaly inbuilt. Giving problem in battery backup. Because it is inbuilt, i don't touch it, see it & also don't known what happen to it. It gives me just 2 hours. I request your micromax care survice to fix this problem. But they ignoring & saying that i am damage it so they cannot take battery's responsibility. I use company models charger daily .then tell me how can i fix this battery problem