Possibly, it depends on the validity of your employment contract. If the contract is valid, and provides for 8 weeks, the employer can deduct the balance from your accrued entitlements.
Check with the Fair Work Ombudsman.
Thanks Rob for taking out time to reply. I checked with Fairwork Ombudsman, providing my company details and the issue I'm facing. They have asked me to take legal help, and suggested I could reachout to JobWatch for further assistance.