Sony Xperia L keeps restarting

[Powdy]

Whenever my Mobile Data is switched on, my Xperia L keeps restarting about 6 times a day, but when Mobile Data is off it doesn't happen!

[Uliwooly]

Test with a new SIM card

[Powdy]

Doesn't work but thank you, I think it's fault with my sp

[Uliwooly]

I don't quite understand, do you have an Xperia L or SP ?

http://www.sonymobile.com/global-en/support/contact-us/

[Powdy]

Xperia L, I mean my service provider, sorry!

[Uliwooly]

Take it to a Sony repair center