Legal Question in Consumer Law in Florida

They cannot charge you twice.

Using a debit card is much like writing a check, ordering that payment be made from your checking account. The check continues to be "good" (redeemable) quite a long time after you write it. So, if you order payment from your checking account for a restaurant bill (by using your debit card), it is up to you to balance your checkbook in order to know that the funds are still available in your account when the bank tries to pay the merchant.

Of course, they cannot charge you twice. But, they can charge you once and a month later.

You can dispute the charge through your credit card company if they made a mistake and charged you twice. If this is the first charge for a bill that you agreed to pay, it is your responsibility to balance your account and make sure you have the required funds for that purchase. If you did so, it would not be an issue that they waited to run it though.