Have you looked for visa expeditor services in London? It would be for a fee but may be the easiest way to facilitated a Schengen visa.
From a basic Google search, I found the following:
http://www.theschengenoffice.com/
http://www.abriggs.com/visa_country_index.php - I used A Briggs to get my UK work visa while in the US...not sure if they could help or not.
Good luck!