Leaving your debit card in the ATM machine is not an uncommon mistake. Accidents can happen to anyone, but in a situation involving private information and money, it can be easy to panic. Luckily, banks have set protocols for this situation.
The American Bar Association says that the ATM will eventually suck your card into the machine. The action the bank takes regarding the card may differ from bank to bank. Some banks will allow you to retrieve your card the next day, whereas others dispose of the card immediately.
Call or go to the bank as soon as it is open and explain your situation. If the card is still intact, it may be as easy as showing proof of identity and/or providing a pin. If the ATM belonged to a different bank than your own, you may not be able to retrieve your card.
Provided no one nearby saw your pin number, no one is able to access your account. This statement is especially true if the card has been pulled into the machine. Despite this, it is important to alert your bank of this incidence.