A thing you can do is to contact your
Congressmann (the Representant of the
district where you live).
In your letter (or email), detail WHY you need
your case processed asap . If you
have a good reason (travel, govt. job opportunity, etc.),
this helps.
Do not complain, just ask very politely,
give supporting information, and hope
for the best.
Normally, the Congressman's office will
ask you to fill out a release form, and they
will inquire on your behalf with BCIS.
This told, all this may take some time, and
you may well get your OL in the mail
before any action being taken.
In addition, due to the elections, some
Representatives were not reelected and
are shutting down their offices. You will
have to do your homework to find out whom
to contact.
In any case, there is nothing to loose doing
this. Helping their constituents with immigration
matters is part of their job.
Good luck.