Okay, so I have the iPhone 5 and I just switched from Vodafone to EE.(both UK mobile networks). The voice/phone calls part is working fine but if I try and connect to a webpage I get the following message "Could not activate data network" and underneath that it says "you are not subscribed to a data service". Now I wasn't sure if I did the unlock process correctly as it was originally locked to Vodafone, but I think I did as mentioned above I can do voice calls. Anyway, after a reboot and resetting all networks settings I tried a restore again and this time as a new phone. That worked and I got data working, but then I went back and did a restore from back up and its gone again. Clearly something in the backup is not set up correctly for EE. So what to do? I'm not prepared to set it up as a new phone and loose all the stuff in my back up (mainly texts which I want), would a restore but from iCloud perhaps help?