Anti-theft Controller problems of the 2008 Cadillac CTS

I own a 2008 Cadillac Cts with awd. I bought it in December 2007. At around 7000 miles in mid-February 2009 my car would not start. The antitheft device was activated. A roadside assistance technician came out. He said it was a defective battery which he replaced. Three weeks later I tried to start the car & received a dashboard alert that the battery registered low voltage and could not be started. The car was towed to the dealer who worked on it for two days. They told me that "maybe" the computer was being turned on when the car was shut off. Their "maybe" answer made me feel they were just guessing. They told me they had corrected the glitch, charged the battery, told me the battery was fine & that the car should be fine now. Last night, April 15, 2009 at 10:00pm my dashboard alerted me that the battery was too low to start. I called roadside assistance who could not get it started either. On April 16, 2009 at 8:30am I had to have the car towed into the dealership again. The service technician again said my battery must have a defective cell. This is the same battery that they put into the car 6 weeks earlier that they said was "fine". I am now awaiting their "professional" diagnosis. Do you have any other complaints of this type on this vehicle? also do you know if this car can qualify as a lemon under federal & NJ lemon laws?.