Before you just toss it, take it apart, there may be something marginal about the main power leads where they connect to the cell tabs. These are known to have probs - they've also had soldering quality issues. This may be the lipo that has a small circuit board inside and connections are not good enough to let it flow current.

But, def agree, its not worth the bucks to send it back. This unfortunately is part of the zippy experience.