Where Can I Ask for a Refund?

[ElPolloDiablo]

I have bought a GS911 Wi-Fi last Summer. It worked pretty much flawlessly until earlier this year, when after a firmware update I started having serious problems conencting to a WiFi network. After several system recoveries, it deigned itself to start working again.
After the last update I am experiencing yet another host of WiFi connectivity issues, but with a new twist: each time I try a system recovery I get a 400 Error Message. In short I cannot even attempt a system recovery anymore.

At this point it's obvious my unit is defective. If it cannot even run updates anymore without experiencing connectivity issues there's something seriously wrong with it. I don't want a new one: I just want to ship it back, get my money back and be done with it. Who do I contact?