This number called me as well and said they were from citibank. I was suspicious and called the number on the back of my citi card and they verified that it was a Citibank Fraud Department number.
This was the Citibank early fraud warning department. They knew both my wife and I, how much the charge was, and the date/time it took place. All they wanted was a yes or no, did I make the charge or not?
Call was from credit card company to verify a charge on my card.
The charge had not been made by me. They said the card was to be canceled and the charge cleared. They never ask for the card number or anything other than to verify that I had the card in my possession.
I called the credit card company the next morning to check the status. It had been cancelled due to fraud and a new one was to be issused.
Saved me over $1000 in charges.