Sony India — Sony xperia z2 touch problem

Address:	New Delhi, Delhi, 732101
Website:	www.sonymobile.com/in

The screen is not responding at all, it keeps touching on its own. As it has a physical button for camera so i can open camera by pressing the shutter button, it also captures images but not by touching. So please suggest me if the touchscreen replacement would work and how much will it cost because i have given my phone to sony service centre and they told me it will cost me 29000/- INR to repair my phone so i took my phone back as its a huge money for me to repair. Please help.