Hi seant,
How many employees are there in the company?
If your employer does not need your job to be done by anyone anymore due to lack of work and you could not have reasonably been given another job within the business then (depending on the size of the company) you may be entitled to a redundancy.
This could be why your boss is now purporting to rely on a prior verbal warning to dismiss you, because he doesn't want to pay redundancy package.
Unfair dismissals include situations where your dismissal is harsh, unreasonable or unjust, however not if it is a genuine redundancy. Small businesses of less than 15 employees, must comply with the Small Business Unfair Dismissal Code.
Check out this article for more info about unfair dismissal:
Unfair Dismissal and the Fair Work Commission - Legal Blog - LawAnswers.com.au