car wont start after i replaced the starter that was installed in april '12.

This may be dumb question, but have you checked the battery and the connections? Now, when I say check, I don't just mean look at them, but actually remove the connections, *thoroughly* clean the terminals, inspect the wires for corrosion damage, and test the battery out of the car. I can't tell you how many seemingly enormous problems that come into the shop turn out to be nothing more than a bad battery connection or faulty/missing ground.