When my JXD 7800 died after about two months, Willgoo stood by their guarantee of a six month warrantee:http://www.willgoo.com/shippinginfo.html?zenid=eee8d1fbcd23432822929576c5d5e463
I contacted their customer service via email with my purchase info, I tried a few technical requests that they asked of me to verify its condition, and they agreed that the death was not my fault. Then a little negotiating ensued (Sure you don't want t buy a new one? After all, shipping is pretty expensive / Nope, I just want a replacement, perhaps for the cost of my shipping back to you? / Well, how much would that be? Etc.).
In about thirty days from my first email to them, I had a new GPD G7 with minimal fuss and out of pocket expense. At least, minimal for a US person dealing with China (with a fifteen hour time-zone difference from US Pacific, it's kind of like emailing the future...) But, then again, I knew it wouldn't be like heading over to the local Walmart.