Sony India — Mobile handset not working ,behaving irratically

Address:

Kolkata, West Bengal

I have purchase a sony mobile Experia dual E1 on 19.05.2014 .It was 1 year warranty .It first problem on 12.01.2015 than I deposited in authorised service centre at techno plaza at garia, 700084 phone[protected].They were solve mobile hardware and software problem on 1 week and return my phone .BUT I big confused when I meeting our office staff automaticaly switch stop and do not open this phone .It is lose my prestige in our office . I dont know what is the problem ?, because I am not a technician. I think sony is the bigest company in the world and good reputation of all category man and women of product .Please solve it, please solve it, please solve it.