Is a transit G required if transiting via 2 cities in China?

Canadian flying from Tajikistan to Cambodia and will transit via Urumqi for 2 1/2 hours and Guangzhou for 7 hours on the same day. Will not be leaving either airport. I've checked with the visa service here and they didn't know. They recommended I contact the "general station of immigration inspection in Urumqi" to verify. I haven't been able to figure out how to contact them