I don't think he made this thread expecting anything other than an answer to the question "Can the union help me get my job back?"
It's a reasonable thought. I mean, he's not paying them now but he did fork over a good portion of his weekly UPS income to the union-- it's not much of a stretch to hope that they might be able to help a member retain their job after a mistake.
I do think OP's SOL with regard to retaining his job, seniority, pay rate and benefits, though, regardless of what the union might be able to help with. There's a chance they could get you back in, I suppose, so I wouldn't give up if I were in your shoes, OP. I just think you're in a situation where the company, if they want you back, would much rather rehire you than to reinstate you.