It was bad enough paying 3 months line rental upfront never mind 12 months !
Did they con you a while back when you had two lots of line rental in one bill?
They tried that with me but I got it removed as I said I had always paid in advance and I had.
My BT bill used to be between £45 and £65 a month, but BT wanted to charge me £4.50 for paying my bill on time, I arguged about this with the CEO but never won as he said it was a corporate decision.
But in the end I gave in and told him I was making a customer decision and took nearly all my calls away from BT.
Then I ticked the direct debit little box and kept on paying as I had always done (online banking) and saved myself another £4.50. Thanks BT.
That £4.50 charge must have saved me £1000 over the last few years.