When you report a fraudulent transaction, the bank starts an investigation process. This involves reviewing transaction details, such as where and when the transaction took place, the merchant involved, and any past history of similar activity. The bank may also look at security camera footage if the transaction occurred in person. This process may include collaboration with the merchant and law enforcement agencies. If the bank determines the transaction was fraudulent, the bank typically refunds the money to your account. Note that vigilance on your part also plays a significant role in detecting credit card fraud. One such instance is being able to spot a credit card skimmer.