You have a CCJ. Have you not noticed? Paying CE will not remove the CCJ and it will remain on your credit record for 6 years causing until financial pain.
You need to immediately contact the CNBC and whilst on the phone find out who, if anyone was acting for CE and on what date the CCJ was filed. Also, whilst still on the phone, you need to ask them to email you the details of the Particulars of Claim (PoC).
Once you know that we can assist. If you do nothing, you are in for a world of hurt.
Why do you think you never received any notice of this? When you moved, did you update your V5C for the vehicle. This is the most common reason for not receiving notifications. Updating your drivers licence does not automatically update your Registered Keeper data. Get that done now, online and only takes a few minutes.