My K750 is not starting. On switching it on the initial white screen is only blinking. IMEI 35437701-746627 plese help

I have purchased K750i (IEMI: 359672005627625) on 14/10/06. Recently some how there was a problem with keypad in my cell & then I had given to Service Center (code: 2000998) at Valsad-Gujarat, India. They found the problem Fault code: 16HW part. Part No: 5018010215R). They had formatted all my data from my cell without any intimation to me.

The WO No: SE07-B26-0703013.

Instead of this cell they gave I used one K750i (IEMI: 353406015739214). But within day the software was corrupted. So I again gave to service center. The WO No: SE07-B26-0709005 dtd: 09/july/2007.

I am not satisfy with Sony Ericsson service so I request them to take any further action to rectify my problem & I hope that I will get the new K750i with sealed one.

The contact no of service center is +91-2632-258355/259452 & my contact no is +919825413556/+919879599335.