This is indeed Charter Communications. When connected, there is supposed to be an automated message... often a satisfaction survey or a message explaining that a service call has been scheduled and you are to press "one" to confirm the appointment. I got three of these "blank" calls via my cell phone today with disconnects at 4 secs instead of a message. I reported the problem and hopefully, it can be fixed as unconfirmed appointments are cancelled. (No one give a %$#@*& about the satisfaction survey.)