Welcome to Vodafone Community
If you are PAYG and not pay monthly your account would not be restricted. The first thing to question to ask is are you able to receive calls and texts?
Although the obvious, presumably you have a bundle or added credit. It might be worth checking your My Vodafone Application, this will give details of active bundles and credit.
If you need help live chat or calling would be your quickest option: Contact Us
You may have infringed Vodafones fair usage policy in some way @mazzz
If they feel this warranted they can indeed restrict a Vodafone Payg Account.
As a process of elimination can you try your sim card in another phone to rule out the phone or sim card please.
Try Live Chat or the Vodafone Social Media Teams via Contact-us-for-account-specific-queries can access your account and check things from Vodafones end to see if it has been restricted.
A Vodafone Highstreet Store can access your account to check too. They accessed my Payg Vodafone Account recently for me.
There is no account access 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.