Hi Paula,

If you've discovered this before paying for the car, then that's not a major problem. Either pull out of the purchase, giving your reason, or ask for a discount.

If you've already paid for the car and taken it away, then things are a little trickier. Before you do anything else, make sure you get a copy of the advertisement for the car. Then contact the seller and see what they say. Make sure you know what you want out of this now - i.e. do you want to give the car back or just some of your money back? Make it clear from the outset what you want. Also, bear in mind that those items alone won't have made a huge difference to the price of a used car. 

Best of luck.