Tokyo-Shanghai-Vancouver(Canada) via Beijing

Hi.
I wanted to take Air China from Tokyo to Shanghai and with 144 Permit I was planing to stay in Shanghai for 5 days, then back to Vancouver (Canada) using same Air China, via Beijing as Air china doesn't fly shanghai-Vancouver route. I was refused to board, left in the Narita airport without no way out. I had to pay extra ca$600 to fly from Naraita to Beijing. Is there anyway I can get that extra pay back , as I had paid for Narita-shanghai-Vancouver flight?