Thank you all! I am still trying to find an organization that's a good match - it just gets frustrating! I had a volunteer gig I loved a few years ago, but when they replaced their coordinator with someone who wasn't competent (or friendly), I quit (along with half the other volunteers).
Perna, thank you for the link. The suggestion about vetting these organizations ahead of time is a good one. I do look at websites and financial records on Guidestar (I don't want to volunteer for an organization that pays their CEO $500,000). I also try to scope the place out in person.
I think I need to start volunteering for one off types of projects at an organization before signing up as a volunteer. That would probably weed out some of these more ridiculous scenarios I've encountered recently.
Sister Rags, in my experience, even though you'd think a large organization would have their volunteer process nailed down, they can be just as disorganized as a tiny non-profit. I hope NAMI gets back to you soon -- although from now on, when an organization doesn't get back to me, I'm crossing them off my list. I 'chased' the last organization I was trying to sign up with and the more involved I got, the more I realized that I could not cope with that level of chaos.
H3rmit, I don't think anyone could pay me enough to be a coordinator myself

I actually interviewed for a job doing that and decided in the middle of the interview that there was no way I wanted to do it. It just sounded like torture, dealing with both customer and volunteer complaints!
Little Lulu, I think you are right that volunteering is not for everyone, and it may not be for me at the moment. There's something about writing off volunteer work that makes me feel selfish, but maybe it's easier to get over that than to keep banging my head against the wall

Like your husband, I do help out elderly neighbors and it's much more fun than waiting for someone to get back to me.