72 hours free visa advance information to Shanghai Airport Immigration

We are US Citizens intend to travelfrom BKK-SHANGHAI-TOKYO-BKK taking a less than 72 hours holiday in Shanghai. And then onward to Tokyo.
Airline staff from Bangkok does not know this new facilities. If Airline cannot take our datas and make advance information to Shanghai Airport Immigration, how can we be approved in advance or can we proceed ourselves at Shanghai Airport Visa free counter and get the permit on arrival ?