I'll try writing to the commune though I have to find the right address for such a letter.
The funny thing is that when I left Switzerland in 2008, I gave them a copy of my departure notice but now they say that's too old. What BCV is doing is basically stalling: I want to transfer the funds from my pension fund there to my account and they ask for all strange things: I'm working in US on a H1-B. They already have copies of my passport, my driving license here (issued after I left Switzerland), work contract, lease agreement with my landloard, letter from my employer, ... They asked for my work permit and when I explained that in US you don't have work permit similar to Switzerland but rather have a visa in your passport and just a simple i797 notice of action, they just repeated that they need a copy of my work permit!