^^^ THIS^^^
I agree with JNB and would recommend hanging in there and being patient. The Referral list can remain open/ active for up to 6 months possibly. I would not recommend calling anyone, because that could backfire if the perception is that the applicant is "pestering". You have jumped through several hoops so far, and just need to wait it out. In the mean time, do not hesitate to apply to any other open positions to improve your chances.
V/R