my supervisors say that since i use to unload trailers in 50 minutes, that i have to do that from now on. everyone else takes about 70-80 minutes per trailer. they tell everyone else that 60 minutes is the goal time. im part of the union. they also are moving non-union workers into the preload and saying that i dont do well enough in the preload. i've never had more than one week to work any of the pulls in the preload. what can i do?