Sony Xperia — Sony Xperia U - Handset is dead thrice in a month

Hi. Myself Apurva Petkar from Nashik. I bought a Sony Xperia U ST25i handset on 23rd March, 2013 from Impressions Shop, Shalimar, Nasik. Within 5 months it had a weird problem that it got switched off and then was just dead. It was not even charging. So I took it to Sony Service Center in Nasik located at Canada Corner. I was told not to let the handset completely discharge. This same problem I faced within next 15 days again. When I took it to the same service center they again told the same. Within next 8 days I again faced this problem but this time my mobile was not discharged at all. In fact it was completely charged. When I took it to the same service center they told me, motherboard has to be replaced and it will take 8 to 10 days. But now when I called them after 8 days, they said Sony company has not sent the part to us which is to be replaced in the handset. My complaint is if within a month the handset goes out of order so many times, and every time I lose some important data from my phone, it’s a big loss for me and I want my money back. Also the service of the service center is just worst and the service center just does not give satisfactory answers to any customer. Also the job sheets they prepare with just no care at all. Whenever I called the toll free number to get the ticket number, they always say take backup from your phone. But the service center never allows me to take back up of data from my phone. So now I am very much frustrated out of all this and I want my money back that’s it.