Tata Motors — electrical fault (battery or wiring)

Address:

Lucknow, Uttar Pradesh, 226024

I have complaing in my tata ace vehicle which i have purchased on 14-8-17 at mgs auto fab, lucknow.
After then i make many complaints for the starting problem in my vehicle, but upto now it is not corrected.
What can i do??
my vehicle no. Is up3jn0509
The tata motors service centre employee tells nothing to resolve this problem. He kept my battery & told that to come after 2 weeks to know about battery position. If your battery changes then good, otherwise take your old battery & you purchase new one from market.
Now my question is that, when my vehicle & battery is in gurantee then why should i purchase new one.