Ring 789 from a Virgin phone, or 03456000789 chargeable (9 til 6) and be prepared to do battle. If Virgin can't resolve it, they are sending out new phones.
If you want to avoid the above, or can't wait, borrow or buy a (cheap) unlocked phone.
Hey @pumas and @HooePA,
I will be happy to help if either of you need any further assistance from us. If you do, please let me know.