tony_miser:
Which side of right you are on depends on a number of things. What the original Terms & Conditions said, what the July 2009 letter said (perhaps) what you made of the information that the new rate would be 2%.
I take it you are saying you thought you had been informed that the rate would be 2% but you didn't realise you would be signed up by default?
Scrutinise the Terms and Conditions and the letter to see if (in hindsight) whether what has happenned can be fully explained by the wording. Also whether YBS have fully complied with any notification requirements referred to. Can you identify any clause you consider "unfair"?
Sorry the answer to your question is probably yes, unless you can find some unclear wording to challenge.