I was denied boarding but I believe I fit the description of the 72 hour requirements.

I am Canadian and My original flight itinerary was:

Sa 31/03 13:20h
Vancouver (YVR) International
su 01/04 16:35h
Shanghai (PVG) Pu Dong
MU 582 Economy (12h15m)
mo 02/04 08:45h
Shanghai (PVG) Pu Dong
mo 02/04 15:05h
Kunming, YU (KMG)
MU 5505 Economy (6h20m)
tu 03/04 14:20h
Kunming, YU (KMG)
tu 03/04 15:15h
Kathmandu (KTM)
MU 757 Economy (3h10m)
mo 23/04 16:15h
Kathmandu (KTM)
mo 23/04 21:25h
Kunming, YU (KMG)
MU 758 Economy (2h55m)
tu 24/04 08:40h
Kunming, YU (KMG)
tu 24/04 09:05h
Vancouver (YVR) International
MU 215 Economy (15h25m)

I was denied boarding in Vancouver as I was told my layover time in China had to be less than 24hours. But both cities are on the list. I had to buy a new ticket and fly the next day. Any advice or help would be greatly appreciated!