It's in all the literature included on pretty much everything you buy. Plus you can look up warranty policies online. Trust me Google has their bases covered in your case.
Just chalk it up as an expensive lesson learned and next time avoid eBay and Craigslist if you want a warranty thats honored by the manufacturer or the company that sold it to you.
It's also included in the ipod and iphones, warranty is void is you buy it and this is going to go with this phone too.