Sony Ericsson Vivaz — waste mobiles

I bought sony ericsson VIVAZ in march 18th of 2010, but i'm facing so many problems with this mobile like automaticall turning off, the wifi is not connecting properly, camera screen blinking with black lines, it doesn't shownig picture clearly, and sometimes it is showing emergency calls only like that so many problems...due to lot of problems i gave it for repair but again same process started then i have replaced it..but again i'm facing the same problems.
what i have to do?????
I recommend all of my friends to do not purchase sony ericson phonesbcz of these all problems.I'm paying 35£ every month, it is my waste of time and money.

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