Faulty Xbox bought as Christmas present. Not received a single response from supplier. Very disappointed.

I've emailed Incredible Connection numerous times without a response. Xbox was a very expensive gift for husband, stated on site that it has built in Wi-Fi. Xbox has never been able to connect. No network showing. Even when router is placed within feet of xbox. Which means that there is a problem with the internal wireless receiver. I now have to spend more money and buy an external wireless adapter, or get the Xbox repaired. I believe the Xbox was faulty when I bought it online. Why have my questions not been answered? Why have they not offered to replace it?