I have had a talk with a lawyer and contacted the car yard they dont seem to keen to help out . this is what the lawyer had to say.
The car yard appear to have acted in contravention of the Trade Practices Act 1974 by falsely representing to you that the car was a particular model. You have purchased a car believing that it was a more expensive model than the one you actually bought based on the description provided by the salesman and in the documentation provided. Whilst ultimately you could take the car yard to court, you are better off first contacting the car yard with your complaint and asking for your money back and to return the car or for them to compensate you for the difference in value between the two models. If they are not prepared to be reasonable you could mention that you will be making a complaint to the motor trades association and will have to consider legal action ultimately based on a the Trade Practices Act. If you demonstrate that you mean business they are more likely to negotiate a solution with you. You are well advised to keep a careful note of all conversations you have. If they are not prepared to be reasonable, you might find that the motor trades association of Australia are of assistance before considering legal action.