After speaking to O2 today and asking if the problem in OX14 was in anyway linked to mine they were able to tell me that the engineers were onsite and working on trying to find the problem today, I think they said they arrived there at about 12:00, glad to hear that it's back up and running now.
@ Jawswing, As it is a known fault, and they are working on it, do you have any more info at all? As O2 admitted to me today that there are quite a few customers experiencing the problem, but wouldn't give me numbers, and that it wasn't limited to being just the iPhone, it covered quite a few different makes of phone and areas. However, they didn't really know what the problem was, or at least wouldn't tell me or admit they knew! It was being investigated in my case as a network problem, but in other cases would not be investigated as a network problem, as often the network team would return the problem as a phone or SIM card problem, they've said the masts in my area are working fine, phone traffic is passing ok and nothing is flagging up as a fault. However they do admit there is a problem, but as yet, no one can tell me what, when it is ever likely to be sorted or what I can do in the meantime! There was talk of them contacting Apple about the problem in depth, but surely this should have been done before now and if it is not limited to just the iPhone, then can it be lots of different manufacturers problems?