I dont remember what number I called. It was the local USCIS office, which was vaquely listed because I don't think it was assigned to receive public call. There wasn't even any automated greeting, I got to a person right away. I dont remember the number anymore since my computer history folder has been purged. I am sure you will be able to find your local uscis number if you did a little search, or someone here might have the answer for Kansas DO.
Anyway, I got my oath letter today!!! It's a BIG relief to actually know that I am thisclose to getting my citizenship. It took about 5 months from start to finish, the longest wait being for the oath letter.