Did you buy over the internet or at a shop? And for which ever do you still have a reciept of it? Its possible that its the fault of the supplier (eg, fags in the warehouse playing football and breaking everything) and O2 are oblivious. Im not sticking up for O2 btw, I hate all mobile phone companies: (this is just my story, not related to this topic) I've had my phone stolen today and when i went to block it, because I hadn't registered (because it didn't work) they said I can't block it without the sim card. Meaning the phone has to be infront of me to block it. Anyway the only thing you can do is keep trying. The urge to become arsey and shout will beome greater but you must resist otherwise they'll just ignore you completly