They stay on the line for a couple seconds after my answering machine finishes it's message and you can hear a bunch of noise in the background like a call center or something, but the person calling doesn't say anything. They've called several times in the last week including calling on Saturday and Sunday.
The caller didn't leave a message, and I wasn't going to answer it because I don't know anyone at "Nandorf Inc". I did Google the company and here's what I found out: 27161 Tungsten Rd, Cleveland, OH 44132. Owned by Jack Koll, this is a very small outfit that cold calls people and asks to pick up appliances, clothing and other household items. They then sell these things on in bulk to resale shops, and if the items are nice, they even use Craigslist and Ebay to sell things on at a profit. They are NOT a charitable organization, unless of course, you're counting Jack Knoll.
I think this is the start of another unwanted caller... Just got a call for the first time from this number, and already I'm fed up. Caller ID just says: Unknown Name
Caller ID said, "Nandorf, Inc." They call to ask if you have any donations for the various non-profit organizations like Vietnam Vets Purple Hearts, etc.