raglan,
The code of conduct is not a mandatory (must do).
At its best, it is a wish list on what finance type providers should do.
FSO have a proven history of siding with the Banks ,since FSO appear to take a largely contractural/legalistic view ie what you signed ,on any case where it appears there is a trend that will cost the banks in a general way.
The Code does say that Banks should act in a clear unambiguous way etc , the important word here is SHOULD , not must.
I think your chances are very poor but maybe other posters have hope for you.