Gosh! I wish that I too had a truckload of that "I am da union manz an you Wal-mart shoppers are destroyin' Amercia" rhetoric for you, but I'm fresh out. (Plus, it's more like "You Wal-mart shoppers are wrecking our cushy arrangement.")
Anyway, I did want to explain the situation with your union dues.
First, you can resign your union membership at any time, with no notice.
The issue of dues, however, isn't the same. When you join the union, you normally sign and agree to pay dues for the life of the current labor contract, or for some other length of time specified in the agreement.
At the end of that period, your employer can (and will) stop the deduction of union dues, but YOU have to tell them to do so. If they do not receive written notice from you, the dues will continue to be deducted as they assume you are still a union member.
You expect the union to fess up? HA!
Union dues