I'm pretty much in the same boat.. called O2 customer services in the morning and am now awaiting a call back from the back office team (the team that apparently get you working) within a 5 hours time window. Currently at 3-4 hours so fingers crossed!
Following day I take it down to CPW (the branch that should have received the phone) Gateshead but they are unable to close the order as the kit is (still) assigned to the CPW Online branch code and until they move it to their own branch; the order woill stay open. So.. if the order aint closed then the phone can not be activated. However, I was told at the time (Saturday!) that it should be closed by Monday but to be fair I've never had time to visit the shop so that question is still hanging the air 4 days later. Hopefully O2 will be able to resolve without involving those incompetant eejits at CPW - here is hoping.