Free 72 hours China Visa?

Hi, If I am a Canadian but living in Bangkok so I'm flying from Bangkok to Shanghai and stay in shanghai for only 2 or 3 days, and then want to return to Bangkok after 3 days, do I get free 72 hours if I book a flight with a connection in Hong Kong? For example if I go from Bangkok to Shanghai and then from Shanghai to Hongkong, then back to bangkok?