Sony India — Touch problem, speaker not working

Address:

Mumbai City, Maharashtra

I purchased sony xperia c 3 (black) dual sim on 26th jan, 2015. i came home m very excited to used that phone but when i listen the music then i came to know that the speaker not working ):. immediately i reached the croma shop from where i buy that phone that seller who sell phone to me he told me who convience me that on the same day he replaced my phone but m very disappointed with sony... then i started to use that replaced one phone but within 10 days that replaced phone again having problem that phones touch not working, cell phone continues going hang, then some beep kind of voice comes out from phone...
i request you to sony higher authority to please issue me D.O.A letter plz plz plz... sony authorised service centre and even the Croma people doesnt give me proper response. i am very very disapointed with "SONY" AND "CROMA"...