Your bank should refund any unauthorised transaction, especially if you had informed it immediately as you discovered the problem. It should also refund any charges or interest arising as a result of the transaction.
Your bank can refuse to refund you if it can prove you authorised the transaction - though it can’t just say your password or PIN were used so therefore you authorised it. It can also refuse it if it can prove you were fraudulent (unlikely in the circumstances), or that you did not take proper steps to protect your personal details such as your PIN or password, especially if you disclosed them to a third party.
Unless one of these reasons applies, the bank should make the refund immediately.
Your side of the bargain
Your bank will only refund you for unauthorised transactions if you haven’t been reckless with your details.
So always make sure to keep your personal information such as your passwords and PINs secure. This includes using different passwords and PINs for each card or account you have and shielding your PIN when withdrawing cash at ATMs.
If your card is lost or stolen, or you think someone else knows your security details, contact your bank immediately.