"The router we ship is a Thomson 582n."
Thanks for that Bob. I obviously misread the OP's post as I thought he wanted a Home Hub which I found surprising as I've never seen them available as one of your routers despite Plusnet being owned by BT now.
Newuser, on the Plusnet "Packages" page, click the "Broadband Only" tab at the top. You don't need to switch from BT to get broadband from Plusnet.