I am a homebound disabled person, and this is the phone line to the Modem on my old computer. The Computer picks up and takes voicemails when I am unable to reach the phone, since it's all the way in the back of the house. This number appears repeatedly on my caller ID - and when I AM capable of reaching it before they hangup on my computer's voicemail message, I sit saying, "Hello?" "Hello?" "Hello?" Without response.
Yes, I'm reporting them to the National Do Not Call people - for all the good that does.
Just don't be surprised if they call you not to get a message left or a person responding to you when you answer.