I have just been through a very similar thing with a Chinese company, admittedly not for this amount of money but there are a lot of similarities in that it is not unreasonable to expect that any company selling product actually at least test it before sending it out, particularly when they splatter their adverts with things like " 100% tested".
http://www.geeetech.com/forum/viewtopic.php?f=9&t=15852
That is my similar thread. The company kept spouting about 100% tested and fully working when shipped and "the courier is to blame". I did all the tests they asked and reported the results, I think that would have gone on forever if I had not opened a case on ebay. Once a case was opened they sent another one. It had the same fault and the fault was a set of faulty PCBs. No way were these 100% tested, if they had been then they would have seen that they didn't work at all. Once they sent me the second one then I emailed them the fix pointing out the missing track on the PCB (or lack of it) and explaining to them how to get round the problem without a new batch of PCBs. For me a happy solution, I got a free board and in truth I actually enjoyed learning about the board so thoroughly.