Have called after 9pm about 60 times in the last year. I call back and it states call failed. They leave a voicemail with complete silence!! Have blocked this number. Seems to be a phishing scam, beware!!
Makes no sense to call these crooks back, you're just are signing up for more calls, since they know they have reached Live Number, and also a Live Person who will be curious enough to call back either an unknown number or a known crook. That is scammer gold. And don't bother to press 3 or 0 or 666 to have your number removed from that "call list" or added to their Do Not Call List. There is NO LIST. These are criminals and they do not obey laws.
-- The way out of these 60 calls a year is to ignore and block the calls. And never, ever call unknown callers at unknown numbers back. Be Smart, Stay Safe.