Firstly, a new lease is a new deal and it’s entirely up to you whether you agree to its terms or not.
Otherwise, you can continue the periodic tenancy and the landlord or their agent must give you 60 days written notice of a rent increase. However they can raise the rent as often as they wish (as long as the rent rise isn’t excessive), so they could theoretically get their money anyway.
If the landlord wants you to move out, they have to give you 90 days notice in writing.
This is one of those situations where a reasonable compromise, backed up with a valid lease, would be the best outcome for everyone concerned. But check with tenants.org.au for all the facts before you decide what to do next.