D..
Sounds like someone in another country used your credit card number. No matter that they credited it back. It may just be the beginning of them using your card. Call the credit card company right away and put a stop on that card and have them issue you another number. Are you sure of your other charges?
Sometimes when unsavory people get ahold of credit cards that don't belong to them, they use them to purchase something for a small amount to see if it will fly. Banks actually tend to flag these because they have found that it's the beginning of fraudulent use of cards. It happened to us one time. They charged a dollar at a convenience store. The bank actually called us about it, and we cancelled the card and got a new one sent to us.
Good luck!
Dawn