Called left no message

I normally don't answer numbers I don't recognize, but this one I answered.  No one was talking on phone, then hung up.  After that I have been getting more calls from numbers I don't recognize.  One shows up on an internet search as a spoofed number.  808-354-0074 called twice.  Later, 808-490-6294 called and this one shows up as an invalid, spoofed number.

Showed up on my caller ID as "Billing Only HI."  I didn't answer.  They didn't leave a message.  This occurred on 12-20-2016