Received a call from here, I called back if you listen to the prompts then you can select number 2 to be on the non-caller list to remove yourself from their call list.
A call from this Fremont VOIP number arrived today. When the call rolled to voice mail, the caller left no message, just dead space. This is typical of robocallers (unlawful telemarketers) who use automated dialers to troll the phone lines in a desperate search for suckers.
Poster Grace (see above) has unmasked the caller as Energy Solar, likely one of many scam contractors trolling the phone lines. This is why it is best to let your answering machine take calls from unfamiliar numbers.