Hi lewismu,
Thanks for your post and welcome to Virgin Media!
If your account was incorrectly set up under a new address, once your new account has been created, you will also have to set up a new My Virgin Media account.
If you have received your new account number, please head over to this link so you can create your new my Virgin Media account, where you'll be asked to enter in your account number.
Let me know how you get on from there.
Beth