This is very urgent, we expedited material Saturday delivery at our cost, and also we will continue to expedite more parts.
Initially the discrepancy was believed to be a Mission Plant problem, but we are detecting problems on their shipments as described below.
The support we need is to put pressure on them to produce faster, and expedite at their cost. But before that, I suggest it would be good idea to have some member of our team / sqe to visit them before shipping so we can audit their weighting / quantities before we actually make the claim.  Our Production / Receipts team will do the same, but I imagine they will correct the problem before shipping if there is risk of a charge back claim from us.