blueeve

my boyfriend took Aircanada go back to China from Montreal, he has Canada visa, student permit and entry visa. Every document is ready, but in the middle of the way, he has to transfer planes. One is from Hongkong, the other one is from Singapore. He plan to stay at Singapore for 2 days(less then 72 hours) , then he will come back to Shanghai. He had all the tickets. Before he go, he already call Canada embassy , airport, Singapore embassy and airport to confirm that he can stay at Singapore for 72 hours without traveling visa. But now he is in Hongkong , the airport didn`t allow him go to Singapore. Please tell me how he can do now. He only can stay at airport. If he wants to come back to China, he has to pay $2700 Hongkong dollars. This is extra money. Who pay it?
Aircanada check the tickets first, if the aircanda find that he cannot go to Singapore, aircanada will not let he go. it will not happen this thing. But the aircanada let him going, that mean he can go to Singapore.
1 e7 A" B( S& i! x$ D0 y4 F2 M: L) Tnow, i just want to ask,should Aircanada pay him back this extra money????