I got the nokia lumia 820 as an upgrade recently and its brilliant, the only thing is everytime i leave the house and i disconnect from my wifi my phone automatically connects to the internet and uses up my credit. I know i can go to cellular connection and turn off my data usage and that that prevents it but i really dont want to have to do that everytime i leave my house. Im guessing its something to do with the live tiles or my aps but does anyone know how to fix?