I`m sorry about your problems.
Holding huge amounts of cryptocurrencies in exchange platforms (even big and trusted platfroms) is a horrible mistake.I`ve never used that BTER exchange platform.If it`s located in China it has something to do with the cryptocurrency trading restrictions and the ICO ban conducted by the chinese government.
I don`t think that foreign sitizens are protected by the chinese law in any way regarding cryptocurrency trading.You should talk with a layer from China.
I agree with him, my dear friend and I am sorry about your problems
I don't think Chinese government gives any kind of protection for foreign citizens, especially after the banning of ICO Chinese exchanges, and trading firms have suffered from some big issues like your's , and if you want to know whether can we take any legal actions upon them then you can better search for complaints in search tab which is available on the home page of this forum ( i do not have the link of that thread) or you can try to search on google or any other crypto related website.
I will try from my side and let you know if there is any solution available for your problems, take care, my friend.