When I was applying for my internship, they told me they would let me know one way or the other "Early next week" or before Christmas or something along those lines. When they finally did get in touch with me, they told me they would have a final decision the week of Jan. 6th. My interview was back in the middle of December. They eventually offered me a job, but I definitely understand the feeling that the longer it takes them to decide or let you know, the more you feel like you're not going to get it.

I think it's good you left a voice mail. I would have called too. It shows that you're interested. Keep looking for other jobs, but at the same time, don't lose hope on this one either. Keep going with the "whatever will be, will be attitude."

Good luck with your job hunt!