rang once, hung up, no message.

I had the same thing happen at the office where I work.

Rang a couple of times.  Hung up, no message.

Five calls in five days, all from different numbers but same caller ID - "BAR ASSOCIATION"
Calling numbers:
312-241-1282 (1)
312-241-1280 (2)
773-273-8302 (3)
708-441-3428 (4)
331-330-4003 (5)