You need to obtain the PUK code to unblock your phone now.
Don't worry, this is normal. And you can obtain the PUK code 24x7 by calling this number 1300-820-120. Follow the instruction and there will be an option for obtaining PUK code.
Actually there is no point of doing that because Maxis wouldn't tolerate Hotlink missing SIM card cases. The function of PUK code is merely just for the policy of being there. This is because when you dial 1300-820-120 to obtain PUK code, there is no procedure for identity verification except that you are required to enter the phone number of the SIM card. Assuming that your phone is stolen and the thief manages to find out your number, it will attempt to reset the PIN number (of the SIM card) by just entering the guessed PIN number and triggers the unblock. Then the thief will call up 1300-820-120 to get the PUK code and reset new PIN.
The worst case scenario is that all parties will just have to give up the number because the thief may not take risk to use the SIM card all the time, maybe only on and off (for doing illegal stuff), fearing that it could be tracked down too.
Hotlink is a prepaid service offered by Maxis. Only post-paid users can have the option to transfer numbers to new SIM cards.
The rightful thing to do is to lock your mobile phones with PIN codes. But you don't really want to do that because it is so troublesome. Another thing to do is to note down your IMEI code if allocation is given to the fact that PIN codes for locking mobile phones can be cracked. The instruction to obtain IMEI code is by typing *#60#, as described here.
For Maxis Hotlink users out there, this code is similar to typing *122# to check your account balances.