I think it did. Have you checked your account balance ? They credit it back to you as they charged for the same thing twice.

They did charge you twice actually (as shown in the picture attached). The hold amount usually won't appear in the transaction history/statement. But the important thing is the payment did go through.

Pre-auth is like the bank will actually hold a specific amount of $, deducted from your account, just incase that there are any frauds/additional payments are involved. Maybe you are paying for smtg that has a chance that the payment could be increased (you subscribe additional stuff, etc.), just like petrol stations and hotels.

But in actual fact, pre-auth is actually used because the receiving end (in your case, the australian embassy or smtg), haven't receive the funds yet, therefore they will take the pre-authorization fund from you, and release it back, when your issueing bank (maybank) has the funds transferred to their account.

I'll take hotels to be simple, as it is the easiest to understand The bank will keep a specific amount, lets say RM250, as pre-auth charge, from your account, until the day you check out from your hotel, and the following day itself, the bank will refund it to u, PROVIDED if the hotel never request for additional charges from the bank (items lost from hotel room, towels, etc.). This is to ensure that the hotel do not be on the losing side, as if you're using debit card, once you pay the initial payment for the room, example let's say RM100 for the room, if there is no pre-auth charges, the hotel will not be able to charge you for the damages done in the room if your account balance has insufficient funds.

Hope my long winded explanation enlightens u