Denver Auto Gonzalo Sold me two bad cars in two weeks and refuse to refund my money denver, Colorado

I purchased a vehicle from Denver autos on March 01, 2012. The first car broke down on March 3, 2012. I then asked for my money back but the dealer refused. The dealer gave me a second car on March 6, 2012 that broke down on the March 13 2012. The dealer did not correct any of the problems and simply got the car to run again but the same problems are still present. When i got the second car it kicked when it reversed and he told me it was only because the car had been sitting a while. The transmission in the vehicle is going out and the dealer is charging me 7,000 dollars for the car. A new transmission is a couple thousand and the car is not even worth that amount considering it has 181,000 miles on it. I really need help. I spent the last of my money on that and i have two small children that I need to be able to get around.