Karbonn Mobiles — Found so many problems in mobile,want my money back

Address:

New Delhi, Delhi, 110013

I purchased karbonn mobile titanium moghul, serial no-[protected]
On 1st july 2016 from hello world shop, laxmi nagar and found so many problems from july to october, i submitted this phone 3times in service center at laxmi nagar it self but they can't resolve my issue. I found so many problems such as-can't hear voice properly, phone got hanged in every 2minutes, got switched off any time (Although battery is full). Now getting frustrated from this and want to complaint a file against your company, poor service given by you, i want my money back as much as possible.
Kindly do needful.