There is government agency overseeing car-dealers, you can find it in YellowPage. Call them.
You should be able to get your money back. Period !
Don't let this little thing put you down.
Lesson to learn - have the sales wrote it down what he said.
我非常害怕写东西, 无论是中文还是英文. 但这次不得不写, 以下是我们买二手车的经历: