Welcome to Vodafone Community
May I assume your currently in the UK and using an alternative network sim card that is activated i.e. connects to mobile data etc on the other network.
Also some Samsung phones also need a mastercode also known as an unfreeze code as well as the Nuc.
Customer service on 191 or Live Chat can help you with this.
Current Phone > Samsung Note 10+ 5G _256Gb > Model: SM-N976B.
Samsung One Ui 2.0 / Android 10.
Samsung Gear s3 Frontier Watch.
Have tried customer services and live chat but still have no unlocked phone. was told to email