As this is purely a customer to customer forum, you will have to take the issue up with BT, I received an e-mail and a letter about the changes.
I joined BT last June so am under the 18 month contract period and although I was aware of the changes and where the page on the site was I have never received any form of communication from BT - I regularly check my designated address as well as the BT email address.
I can only guess that people on new fixed contracts weren't notified even if they had add on elements such as any time calls which is the thing that increased for me and was backdated.
I also had trouble with the email link - then saw your link and tried it. It goes fine until the point where you are asked for your broadband number, but gives no field in which to enter said number and thwarts any attempt to email. Am I missing something?