Microsoft — The phone touch screen not working

I had purchased Microsoft Lumia 535 from E-Zone, Viviana Mall, Thane in October 2014. From the past 3 months I have been facing problem regarding mobile touch screen. While pressing touch screen automatically another application starts. Also not able to type due to touchscreen issue and problem face during unlocking the phone. The phone was given to Microsoft Lumia service center in September still facing same issue. I want the defective phone to be replaced as the same is under warranty. Kindly request you to look into the matter at the earliest. Name : Aishwarya Sukale. IMEI : [protected]. Cont No : [protected].