The trick with O2 customer service is that if at first you don't succeed, put the phone down, try another customer services person.
I had 2 attempts before I spoke to a pleasant lady who first said the all O2 phones were unlocked, I then explained that this is true of all except the XDA, she spoke to a support colleague who then suggested I took it to a back street phone shop to have it hacked !!!! I explained that the software hack was not yet widely available, she went away again and came back saying they could do it but it would be very expensive. I asked how expensive and she said £10-£15. I said that that was OK so she said that she would charge £10 as I was so "understanding". This all happened a few days ago so I will leave it a week or so before phoning to find what is happening