hey. I got into contact with them about changing rooms, and they basically said that its not possible. They said its likely to be possible in october(guess its cause people have dropped out or whatever), but said that would be earliest time. I couldnt really see point of planning to move them, unless your really unhappy, as you'll of already got to know your flat mates and that. But that was what they told me in the email. Just try emailing accommodation office.
Hope its of some help