You can ask the committee to reconsider, requisition an EGM to overturn the decision, or apply to the state tribunal (NCAT, VCAT, QCAT etc.) to set the decision aside if it was unfair, unlawful or didn't follow correct procedure.
Tribunal applications must usually be made within 28 days of the decision. The tribunal won't overturn a decision just because you don't like it — you have to show procedural unfairness, illegality, or that the decision was so unreasonable no reasonable owners corporation would have made it.
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