I quickly answered & hung up so they couldn't leave a voicemail. Luckily I have an iPhone and can easily block calls ;) They won't be calling me again.
Just received a call from this number and as I answered I heard "I'm sorry, that is not a valid extension." Then the call disconnected. very odd. probably a scam.
I received an automated call about my "current credit card eligibility". They said to press 1 if I wanted to speak to a live operator, so I did to ask to be removed from this list. As soon as the words came out of my mouth they hung up on me. Scammers.