First thing...there shouldn't be need of visa as this is only transit and you are not exiting airport. So confirm this. If visa is required and you dont have much time to wait then I would suggest to cancel and rebook new. Visa rejection rate by Chinese embassy to nepali pp holder is quite high even when applicant is us pr holder.
Bottomline is try avoiding Chinese itinary. While you enjoy price they offered, soon you will face lots of frustration due to communication issue. Sometimes simple things gets really complex. I was almost about to get deported by immigration officers. When I asked what's going on. There was only two words reply. "GO". "SIT".