refund against Smart Tab purchase

Location/place: Delhi

Name of company/service: Nakamichi Techno Pvt. Ltd.

Before Two month i have purchase a Smart Tab & it is not able to pay service time after time. I had repaired it so many time but still not working. Please help me to refund the claim of Rs. 7000/- form this company.
Details of Company: Nakamichi Techno Pvt. Ltd., Plot No. 284, Lane no. 3, West End Marg, Saidulajab, New delhi-110030