I've been getting the same bill every so often for a while now. I called them and asked what it was about and was told it was for "continued ALPA services and to continue getting the monthly ALPA magazine" or something like that. I told them I wasn't going to pay it.

I wouldn't worry about it if I were you. ALPA National never did a thing for me and just constantly craps on the Comair pilots. F 'em.