Letting Fees Legislation Change 5/4/07

I signed a REIWA (WA) Managing Agent agreement on 11/4/07 which included the following provision "A fixed Letting Fee for each new tenancy of two weeks rent plus GST minus one week paid by the tenant."
The apartment was let from 16/4/07 and on the first statement a letting fee of two weeks rent has been deducted.

I queried this with the agent who advised "Effective 5th April 2007 the legislation changed in that tenants are no

longer liable for one weeks letting fee."

Yet I actually queried the letting fees face to face with the agency manager on 11/4/07 before I signed (as the tenant came from the partment below which had just been sold by the agent and I understood the agent was obliged to find the tenant a suitable apartment.) No mention was made then that the legislation had changed and I would be required to pay two weeks.

The agent seems to have knowingly mislead me. Can anyone out there advise me what the legal position is please?

Thanks ianjb