I have a Vodaphone internet via a SIM in my Volvo from new. It came with 100GB valid for 1 year and when put in the car you need to create an account and activate it.
Volvo have an offer of a free 100GB SIM when serviced, so in Jan I took advantage of that offer as the 1 year was up.
A new account was required and ever since then I get the similar and continuous emails from Vodaphone.
Firstly from the initial account, there is never a link to extend the subscription, so I terminated it and replaced it with the new SIM.
The emails state, that my subscription is ending, my subscription has ended, followed by another email that they have extended by x days as a goodwill gesture and so it goes on.
No idea what's going on with Vodaphone, but it is a nice freebee