Call from the San Francisco area in California? Have done no business with any company in that area. The number is unknown to me, and isn't one from my callers list. Won't answer any call from a person/company that doesn't have an actual name for their caller ID; "customer service" could be from any source, just like the IRS scam calls. No message left, either. Blocked and reported to the Do Not Call Registry.
Call from Cali, unknown number, different state, no good reason to receive a call from this number. Sent to voice mail. No voice mail left. blocking it.
My other half trying to sleep but we have to leave ringer on for his job . I answer it so not to wake him up Said hello and no one in the other end of the line dead silence .