Hi @mushygirl. Which Android version are you currently running? Are you able to try a different SIM card?
Before you ask Vodafone for a Sim swap can you try your Sim card in another phone as a process of elimination.
This is a help thread from Vodafone UK ~ Network-issues-initial-checks-and-template.
Also may I ask is this happening in one place or everywhere ?
The Vodafone Social Media Team's can check your account via Contact-us-for-account-specific-queries.
If you do need to replace your Sim card then visit a Vodafone High Street Store with photo ID and they'll move your tariff to a new Blank Sim Card or ask customer services to post you a Blank Sim Card and them use the Sim swap page found on Vodafone's Support Page.
I wish you all the best.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "