So you're probably on the No rehire list....so what exactly do you expect the union to do for you?
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 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 than they would reinstate you.
[Addition-Edit: Oh! And I'm seriously not trying to be a dick here, but you'd get more concrete answers from speaking to someone from your local about this. A union steward, at least, because he or she'd be able to get you in touch with the people best-equipped to handle this issue, if there's anything they're willing and/or able to do about it. I would hope you'd have at least one of your stewards' contact information... not sure the best way to go about getting that info as an ex-employee, though....]