So basically I took and passed the driving class before peak, although i didn't end up getting to drive during peak, and about a month ago a sup asked if I was interested in Sat air. I said yes and basically he drove all the truck for all but 2 packages when he told me to take over driving. Now I admit i have a "rough" take off ( I only drove a manual a few times in HS to learn how and at the driving school so i have a difficult time finding the sweet spot between clutch and gas on takeoff) and long story short despite having passed the driving class the guy above the sup i was driving with now wants me to DQ myself I asked why and he said I couldn't drive a package truck and its not there job to teach me. I was a bit confused since i had passed the class and was told i was fine and asked him if i could practice driving the truck around the yard on Saturday then to practice taking off and was told no its a liability. Recommendations or advice?