Battery not chargeing

I think that if you haven't used your portable dvd's battery pack and followed the directions about not leaving it plugged in if not using that Kawasaki should be responsible in replaceing the battrey. Why should I be responsible for a battery that obviously didn't do what it was supposed to do. Why should I be the one to pay to replave something that was deffective when I purchased the unit as a package. When I purchased the player at Target, I had good faith that I was purchasing a quality product, I am obviously disappointed in the battery back-up portion of this product. Is there anything anyone can do to help resolve this problem? I am disabled and on a fixed income. I splurged amd purchased this item so I would have it available when I had to be in the hospital waiting for tests or at one of my several Docter's appointments that usually take several hours. Any suggestions would greatly be appreciated. Eugenia Cook Krullsmommy@yahoo.com