hi all on saturday i brought a 8520 from the carphone werehouse (unlocked) and yesterday it wouldent turn on i had an orange sim card in it and i wanted to put an o2 sim card in it so i turned of the phone took the orange sim out and put the o2 1 in it worked for 2min then i turned of the phone and when i went 2 turn it back on again it wouldent turn on i put the charger in it thinking it was out of battery left it over night and today it still wouldent turn on i took the battery out and put it back in and all i got was the red light in the corner it wasent flashing or anything just doing nothing and it went after 10sec i plugged it into the computer and the same thing happened then i took the battery out and left it plugged in and this time it showed a battery symbel with a red line through it put the battery back and tried it still wouldent work plz help