Sony — My phone not working

Address:

Cuttack, Odisha

Sir, I brought a Sony Xperia M4 Aqua on 07.06.2015. First day phone was working good but on 2nd day the phone is blank and not working.then I call Sony support help line.they suggested me to go Sony Service center then I gone to the Sony Service center. I said the problem then they received the phone. Repair and gave me.I came to home. Again the problem begins. Again I call the help line they suggested that again go to Sony Service center. I gone they repaired and again gave me.when i reach the home same problem begins.I have gone 8 times and 9th time technician received the phone and sent to head office for repair and I submitted and said come back after 7 days. Then after 7 days they called me and i received the phone. But next day same problem arise.I told him for replacement but they don't listen. What i do sir? please sir do something. Please..