Don't get mad. It won't help. It's not going to do you any good, and it's not going to do them any good for you to get mad at them. The teachers at our school went ballistic when a case of wine that was believed to have been given to the foreign teachers disappeared on a trip to a wine factory. They had meetings, confronted the foreign affairs officials and tried to hand-carry a letter to the mayor of the city.
Confrontation is a big no-no in China.
A lot of hard feelings on both sides resulted from this. All those teachers are probably back in the States now, and the Chinese officials are still there doing the same stuff. Try to hold your temper. Have a thick skin. You may find that the waiban or somebody sends spies around to check up on you.