Customer release past due quantity issues (Authorizations)

I have a customer where we ship to 8-10 different sites.  They all send 830 releases for us to ship off of, but all of them send them in a little different.  They send in anywhere from 1-4 weeks of daily buckets which we are able to work easily with.  They are a CUM based customer and all of them send in discrete qty buckets.  This issue we are having is that a few of them will leave the discrete qty bucket for the past due amount, but a majority of them will clear that past due amount from the