Sounds like you have everything covered and really all we can do is wish you good luck. No one wants to see someone suffer, but,at some point and time everyone has gotten the screws put to them by UPS if you have been there for any length of time. It took me two years of fighting them and the union over my pay rate. Just keep fighting and hopefully in the end you will prevail. If as you have stated the local has been no help remember this at election time, also as others have said go to your monthly union meetings and let them know who you are.
Good luck