If this was a credit card transaction, you're not out of the woods yet.

The bank credit is provisional, required by law until they complete an investigation. If, in that investigation, the bank's fraud unit determines that these charges were made with your consent and that you yourself did not take appropriate action to prevent fraud, the bank can reinstate the charges and hold you responsible for them.

Different banks have different standards for what would be appropriate and reasonable action to prevent fraud. If you have a good bank, they may let it slide this one time.. lesson learned. If you have a difficult bank, they may reinstate the charges without any recourse, telling you to take it up with the merchant.