Might I also suggest you spend a bit of time at ADSLguide.
It's a great little forum for UK based ADSL users, they've split the forum into boards for all the different providers.
The Orange one seems particularly active ...
thinkbroadband :: Viewing list of forums
If you want to write a Mr Angry letter to someone, you could try reporting Orange to the ISPA
ISPA - Complaints which might get you slightly more speedy leverage than Ofcom.