I don't believe a word of your story and I have no idea what response you're looking for from this forum. Sorry if I'm mistaken, but your story doesn't make any sense.
First, UPS wouldn't allow it because working for free has been against the law since the Lincoln administration. Second, I have yet to meet a driver that would work his 11th, 12th, and 13th hour at UPS for nothing. It just doesn't happen and will never happen. Think about, according to you these drivers are giving $100-$150 a day to keep their manager off their back? Please!
What is the real story?