Subpeona from attorny's office- Legal?

I have a non-profit organization whose bank account was recently frozen due to a subpeona the bank received from the Attorney's office of Mel S. Harris in NYC. While it has a Clinton County Court number on it the court states that the subpeona did not go through them and went to the bank directly from the attorney's office.
I should note, that this attorney claims that the founding memer of the non-profit whose account they froze owes a credit card money, this person never had such credit card and that the NYS Attorney General is now involved.

I have a couple questions however:
1). I at one time was told that a subpeona directly from an attorney's office without any signature from an official court representative was not valis, that they must be court ordered.
2). Does this hold true only in NY, as the headquarters of the bank that this account is held at is in Maine and that is where they sent the subpeona, while the particular branch is in NY. Would this affect why the bank held the subpeona to be true?

Thank-you.