You can contact them on the following email address, making sure you state your application number in the title of the email:
visa_complaintsny@fco.gov.uk
This is the only way to contact then directly about your application (so I am told by the embassy in SD). I contacted them on this email even though I wasn't making a complaint and they replied the next day.
There have been delays in the NY office in the last month due to system upgrades so this may have affected your case? Anyway, email them and i am sure they will reply.
Hope it all works out for you
Daydream