Recommended for admission by the department but still haven't received official decision
Polite phone call to the graduate school.  Emails could very well be received initially by students, and given that many schools are on spring break right now, that could delay them (or just student workers losing an e-mail wouldn't be unheard of).

If the phone call isn't able to resolve any doubts, speak with the department you applied to and they can put some pressure on the graduate school.