One cannot call the Shubert-owned box offices directly. Tele-charge which is owned and operated by the Shubert Organization, is set up to handle any and all calls that would ordinarily have gone to the theatre. By now there are thousands of former employees (like me) who can attest to that fact.
Remember in the "old days" when you called the theatre, invariably you did not speak with someone in the box office, but rather someone in the mail room which was 'upstairs'--away from the B.O.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher