The HR person that contacted me with an interview date and time told me in the email to call him when I arrived to be let into the secure building. I arrived on time for the interview and called. No answer and left a voicemail. He texted a few minutes later and said, "call the main HR number to be let in." I asked for the main HR number and he did not respond. Had I not known someone else that worked in the building, I would not have made it to the interveiw.