Currently Being ModeratedFeb 1, 2013 12:34 PM (in response to thedoctor950)
I'm not sure how O2 operates their network but I would guess that your giffgaff SIM does not use their primary network and is not allowing you to access their activation network. Since your iPhone is locked with O2 it needs to access the O2 network directly to activate. I would suggest going to an O2 shop and use one of their SIMs to activate the iPhone then replace it with your giffgaff card.
Currently Being ModeratedFeb 1, 2013 12:53 PM (in response to deggie)
If I used an O2 SIM card to activate then put my giffgaff SIM card in would it not recognise that the SIM card that I used to activate it is now no longer in the phone?
I am willing to try almost anything and will most certainly try this. Thank you for taking the time to reply.