It isn't Bandai's fault. your tamagotchi seems to have widened its circuits, therefore draining the batterys faster. try to get new batterys at towiz.com.
Did you slam it against something,because if you did, then you need to get a new tamagotchi. if not, then put it somewhere hot. If that doesn't work, then push the reset button. If that doesn't work, then I have no way to help you. :)