The calls are from a non profit company helping people restructure their credit card debt. They call mostly cell numbers but because they are a non profit agency they are not subject to the do not call list. Not sure how they get the numbers but probably use a program that identifies a group of numbers got to be expensive to call those numbers and just leave messages.
Got the same call on my cell phone just now. A computer said "Hi" then hung up. *shrug* Probably a telemarketing scam since I don't know anyone in Missouri.
Received a call this morning (12-9-09). I said hello and was greeted by a man who said hello then said nothing else. I said hello again and was hung up on. I redialed this the number (573-339-7276) just to have it ring three times and then was told by an automated voice that this number had been disconeected.