My k550i mobile phone is generating trouble in network connectivity.I have shown this problem to SONY ERICSSON authorized service center for permanent solution.The service center has upgrade my software version and informed me that the problem has been resolved. BUT, I am facing the same issue with network connectivity.I have tried with two other brand mobile phones, to check whether my Mobile SIM may have problem, but it was not as in other mobile phone, I am not facing any network connectivity trouble.

MY PHONE IS UNDER WARRANTY PERIOD and would require immediate attention.

Kindly suggest the following,

1. I would require the replacement of my mobile phone as it is already been shown to authorized service center .
2. I want to lodge a complaint against the below service center as they are not providing any receipt of mobile repairing which are under warranty period,

Sony Authorized Service center
Neeru Enterprises
B1/38 1st floor, Sector 18 Noida
0120-4241511
0120-4241512

Pls suggest your recommendations at your earliest.

Regards,
Debjeet
+91-9810226390