everbuying return Internet

I bought a smart phone 7100 1GHz 4 inch HVGA screen dual Sim WIFI that describe it will work with GSM network GSM 850/900/1800/1900MHz on Web Site Everbuying.com at Jan 4, 2013. I have check that it will work in AT&T. I received the phone at Jan 30, 2013, but the phone does not work with my sim card. I have tried many times, but it just do not work. I contacted their support center, but they just told me to try. I told them the phone does not work and I need to return, but they do not want to return for me , just told me to try. Their return policy require the return must in 30 days after receive. According to their behavior, I believe that they are in stall for time and let me miss the return limit. I believe that it is a cheat Web Site.