An update on this, I phoned NTL CS yesterday and spoke to a very helpful Scottish Lady who said, yes it had been enabled on the account and was due to go live tomorrow morning (this morning). I got home from work and the code (*227#) still wasn't working, so I phoned NTL CS again and got put through to another helpful Scottish Lass (could have been the same one - thankyou if you post here) who put me through to an Indian Sounding Gentleman in faults. He confirmed that yes it has been enabled on the account but hadn't been enabled on the Switch so he did this straight away and when we got off the phone, I dialled the code and it worked first time.
Well done NTL (eventually
)