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This error code has surfaced in other threads @Eoinc312 and looks like you'll need to contact customer services on 191 or Live Chat.
Or the Vodafone Social Media Teams here will be able to help. You would need to contact them via the routes in Contact-us-for-account-specific-queries.
Unfortunately there is no account access based help via this forum anymore.
I wish you all the best with this situation.
Current Phone > Samsung Note 10+ 5G _256Gb > Model: SM-N976B.
Samsung One Ui 2.1 / Android 10.
Samsung Gear s3 Frontier Watch.
Samsung Galaxy Buds.