Originally Posted by Steve-Hostirian
Actually, phone calls are a good thing even if it is fraud. Sometimes you wind up alerting the real card holder that their identity has been stolen.
This is a great point, they will also be grateful that you alerted them so they can rectify the issue as soon as possible. I agree with the others, give the client a call, be friendly and introduce yourself. Explain the issue, and confirm all is good, and continue on with the order!