Fair Work Australia probably did not hear all the facts and in any case it is not entitled to provide legal advice. Please read this question “Do courts and tribunals provide legal advice, and should I refer to the courts and tribunals as my first port of call?” for further advice.
You have a right to claim unfair dismissal and the company cannot argue that you were dismissed for operational requirements.
You have a good claim because:
1. The company did not give you any procedural fairness;
2. There were no performance issues affecting you; and
3. There were jobs for the sub-contractors which you could have worked on especially as the company had recently supplied you with a good set of tools.