You got caught by one of the tricks they built in to cost you money after the sale. General Motors and Volkswagen are by far the two most customer-unfriendly companies in this regard. You must never disconnect the battery or allow it to run dead. Some models will not allow the engine to crank. Some will allow the engine to start but the speed won't increase when you press the accelerator and it won't come out of park. You must drag the car onto a flatbed truck and have it towed to the dealer to have them unlock numerous computers. Those cars have the infamous throttle-by-wire system that put Toyota in the news last year.
Sorry for the crummy news but call the dealer can get out your wallet.