why would I need to replace a Alternator and Battery with only 33,600 miles? on 2007 Chrysler PT Cruiser

My PT CRUISER has only 33,600 miles.When I try to start my car it would not start.But the radio and lights came on.The alternator light came on and stayed on.I towed my car to a shop. The shop said the alternator killed the battery. my question is why would my alternator go bad when I have only 33,600 miles on the car and its only 2 years old??To replace the alternator and battery cost $613.30.Which I was not happy to pay.Thank you for your time. Cynthia

Asked by for the 2007 Chrysler PT Cruiser
I am sorry to here your car with such low mileage and so new has given this problem. A battery should last 4 perhaps 5 years and the alternator one would expect 100000 miles. If the voltage regulator in the alternator failed it would overcharge the battery causing the plates in the battery to buckle rendering the battery useless.