Non disclosure of accident damage and false petrol usage spec

I bought a car 2years ago as a run around everyday mummy car. They lied about the petrol usage sticker which said 7.8ltrs per 100km on the windscreen but the car uses between 13&14ltrs per 100km! I have been trying to sell it for the past 6 months but all dealerships that inspect the car tell me that it has been in an accident and show me the evidence on the car .this wasn't disclosed to me by Northcliff cars I thought I was buying an accident free car! The consumer act clearly states that they should have disclosed this information to me. I have been told by the dealers that if a dealership discloses that the car was in an accident they won't be able to get finance from the bank. Don't waste your time!