Credit card processors have guidelines in place to prevent fraud, and you can sign up for programs that alert you when signs of fraud appear on your merchant account. However, it is impossible to avoid fraud entirely. When it happens, there are steps to resolve the situation:
Contact the payment network to cancel the transaction.
Reach out to the bank or credit card company that issued the account and let them know fraud has occurred.
Ask the credit card issuer to contact the consumer whose account was used fraudulently.
Offer identify theft protection to customers whose details have been compromised.
The exact steps you should take vary based on the circumstances. In most cases, credit card processors have fraud teams in place who can guide you through the process.