Firstly, you should contact the inspector you appointed to carry out the building inspection and try to resolve your complaint directly.  If this is not successful, you may want to contact the company that employs the inspector.  In Australia, the building inspection industry is largely unregulated and no formal qualifications are required to advertise your services as a building inspector (except in Queensland).  Before you employ an inspector, you should check the person you employ is a qualified builder, engineer or structural engineer, or has similar appropriate qualifications.