Not eligible to pay annual line rental

[#1]

When I joined PlusNet a few weeks ago, I'm sure the guy on the phone said I'd be able to opt for paying my line rental annually as soon as I was up and running (I like paying annually, because it's convenient and it saves me money).  Then the other night I was on the chat line and was given a link so that I could do just that.  I checked the PlusNet website and once again I got the impression I could pay an annual lump sum, which would save me money.  HOWEVER, when I tried to change - guess what? - I would have to upgrade and pay an extra £2 a month to make me eligible.  But that would cancel out my savings, unless I'm mistaken.  NOT IMPRESSED.  Have I been particularly thick in all this, or could PlusNet be more transparent re the line rental?  Maybe I've got it wrong.  Can somebody enlighten me pls?

[#2]

The normal monthly line rental includes a call plan, Weekends for Unlimited ADSL  or Evenings & Weekends on Fibre. Annual Line rental saver doesn't include ANY calls and therefore to keep a call plan you need to add E & W/E at £2/month.
Not very clear at the outset and we've had a few people here fall foul of this pricing...

[#3]

Thanks MisterW - at least I know where I stand for definite now.  Not what I thought I'd signed up for, but hey, light at the end of the tunnel, only 10 months left until I'm out of contract and can start the whole aggravating business over again