Welcome to the community!
Do not attempt to guess your PUK code as incorrect entries may result in permanent locking of the SIM Card.
You can obtain your PUK number by logging into My Account. Once you are logged in, go to View Mobile Service Accounts, and then go to Get PUK Code under the mobile account you wish to get the code for.
Alternatively, please contact our Mobile Support team on 13 14 23 for assistance in retrieving the PUK code or send us a PM with your contact details so we may arrange a call with our Mobile Support team.