IPhone 4 cannot send/recieve calls/texts but is still able to connect to the internet. What is wrong with the phone and how do I fix it?

Question

A friend of mine has an iPhone4 (not 4s) and she has been dropping it when she was drunk. She also lost it for nearly a week and it got handed back to her, luckily. She blocked the phone after she lost it so that other's couldn't use her contract (which is paid by her father). When she received the phone back, she asked O2 to unblock it an they gave her a new sim card and asked her to wait 24 hours. It started working again, for about a day, where she could receive and send texts/calls and Internet - the lot! But after that day, she can no longer get any signal on her phone to send or receive calls or texts. We have tried putting the sim card in another phone to see if that was the problem, but it worked fine with full signal, so we're guessing that O2 aren't the problem. I'm guessing that it is the phone but I'm not sure whether it's a hardware issue or software. We've recently installed the new iOS5 today and it still doesn't work correctly. Do you think that some hardware needs to be replaced? I was wondering if anyone knew if the phone signal and 3G signal run on the same antena or different ones in the 4S?
Thank you for your time and help in advance. Any help/knowledge will be much appreatiated.

Answer 1

oh my god, i can't believe i am having the exact same situation as yours. i lost my phone for about 2 weeks and got it back. when it was lost I asked O2 to block it and later I asked them to unblock it after I got my phone back. My internet seems to be working fine, but I cant receive or make calls. I went to apple store to tell them about that, they did a factory setting, but still can't get it working and later told me that its not the phone's fault but O2's fault because I could see the O2 on top, with no any bars and she assumed that i would not have been able to see the O2 written on top if it wasn't O2 fault. I told them that I can use the internet from O2 however, but in reply she asked me to show the internet (i still wonder what she meant by that), I tried to explain that the internet is from my data plan, but no... she insisted me on showing the internet, i wonder what exactly did she wanted to prove by that. Or maybe she was in a hurry to get home, because it was almost at the end of the day. Anyway I have changed my sim and it seems to be working fine on another phone, but its the same problem in my iphone 4. I haven't been able to use my phone for more than a month now and its really frustating. I have booked another appointment with apple day after tomorrow, just hoping for the best now