We couldn't afford to join ALTA, so we took the less expensive way out, and paid the $195 fee, which I believe is exhorbitant.  We continue to get letters demanding payment.  We have telephoned and left voicemail message, since there seems to be no one minding the store.  The latest letter is indeed threatening and hostile.  ALTA needs as many friends as it can get, and this is not the way.  Maybe they need new staff who know a little bit about bookkeeping to properly apply credits and paytments.  Since I have our cancelled check and even a Certificate of License issued by ALTA, I think I'll just wait to see what their next move is, rather than attempting to reach someone and clear up their mistake.  I don't have a lot of time to spend on someone else's problems.