Broken Mp3 player

I bought 2 Onyx video mp3s for my kids for Christmas. I bought them at the end of November 2007. The kids received them December 25 2007. In March 2008 1 of the mp3s stopped charging and would only work when attached to the charger. I contacted the company and explained the problem, they said to download some things from the website I did that and it still didn't work so I contacted them again. This time I was told it was defective and to send it in with the receipt, I looked everywhere and could not find the receipt so I emailed again and explained. I was told by 2 different customer service reps that I was probably lying and was just trying to get a free mp3. I told them the exact store and date i bought them and was told they would not help and to throw it away because they would not fix it.