Caller said he works for a credit card company (can't recall exactly who). He asked if I had made a purchase on Master Card and that for security purposes the payment was on hold until I had confirmed I had made a purchase (which I had not made). I told him I had to check and would call back. He then said that the payment would automatically go through if I hadn't confirmed the details within 5 minutes. So I then told him the keep the payment on hold until I checked whether a purchase had been made. He immediately hung up. I then tried to call the displayed number but received a message that there is restricted access to that number. Obviously a scam and may not even be his real number, but thought best to post a comment/warning to others