Sony India — hang and switch off automatically

Address:

Mumbai City, Maharashtra

within 2days of purchase i m suffering from problem its switch off automatically, i gone to service center on 28-5-14 they formatted my phone n said use for two days, if problem occur so you can come back. but then after my phone again started giving me same problem so i go on 2-6-15 and i ask for DOA LETTER BUT THEY REFUSE TO IT, so in that case i want DOA letter and replacement of my phone sony xperia t2 ultra.