It is a company that calls to verify an appointment. Various companies use this to call you to remind you of your appt. everytime i get the call i forget until i look it up.
This phone number belongs to some sort of virtual appointment confirmation center. Although the number has an Orange County, CA area code (Souhtern, CA) , my chiropractor in Northern, CA uses it to confirm all of his appointments. Mr. Max, perhaps the voice message you received got cut off at the time and date?