This person called my business line and hung up

This number called me and hang up.

They ring and hang  up and when you call it directs you to put in extension number

Just called.  Machine answered and they hung up.  Called right back and hung up again.  Caller ID says "FIA Card Services", which is a credit card processing company but...

FIA CARD SERVICES on my caller ID as well.  I have a Mastercard from them but never saw this phone number associated with FIA.

It range a few times. They hung up before voice-mail kicked in.

Presumed SCAM.