If you've noticed a small pending charge ($0-$5) on your card, don't worry! This is a standard procedural check to confirm that the card is active and valid.
Depending on who you bank with, it may take longer for the funds to release back to you. If you bank with NAB, this may take up to 10 business days. For other banks, normally 2-10 business days.
Please note: This is only ever a pending charge, the money never actually leaves your account!