This is TNC or The Nature Conservancy. The number is attached to their donor services. They are no a debt collector, though they are calling to solicit money.
We have been receiving calls from this number always at night. We will not answer because we don't
know who it is and they never leave a message. Very annoying.
I have recently supported The Nature Conservancy, but I didn't expect they would call me without leaving a message. - my sentiments exactly! thanks to Shannon for the info too!
Yes, it's the Nature Conservancy. If you gave them money, they're free to call you even if you're on a Do Not Call list. The reason that they don't leave a message is that there's an automated system robo-dialling, and it connects to one of their operators only if a real person answers. If they detect an answering machine, it disconnects and puts you back into the queue to be called again.
If you want them to stop calling, then _answer_ the call, and ask their operator (politely) to remove your name & number from their calling list. Tell them you'll never give them another dime if they call again; that might help get the message across.