I received the following email just after 12:00 today:
"As promised, we’re getting in touch to offer you an account review. As your contract is nearly up, we want to let you know what happens next so you can make sure you’re on the right package.
Just give us a call on 0800 587 1942 and we’ll be happy to talk through your options."
In fact, I renewed my contract a month or so ago. I phoned Plusnet and the CS got confirmation that the email is wrong and can be ignored.
I am posting this for other users info.