First comment: this forum is intended for Canon owners like you and me to discuss issues. It's not intended as a way to discuss issues directly with Canon. For that, you should call them at the number above.
Just as a comment as a third party observer: I understand your frustation, and perhaps you were wronged. Regardless, if your manner when discussing the issue directly with Canon is anything like your manner in this thread, then I'm not completely surprised that you feel they're not being responsive with you. I recommend you discuss the issue with Canon in a calm, civilized manner. Your chance of having a representative look into the matter and possibly send you out a replacement battery would greatly increase.
It's been a long while since I've sent anything in, but I remember there being a bunch of signs, at the Irvine facility in fact, that said to remove all batteries, SD cards, special accessories, etc before giving to them. I even remember the lady checking before taking my camera. I don't know if this was the case with you, but if you accidently sent in your camera with the battery and were not supposed to, then certainly I'd take a delicate manner when discussing. A battery isn't really a big commodity item for Canon and I've found their customer service to be excellent, I wouldn't be surprised if they righted the issue even if they weren't in the wrong. But they're not going to if you're acting irate.
