Follow up (better news) :
I emailed Anthony at PM USA a description of my problem (one wrong klicky, One missing klicky), including the incorrect figures, as documented by the packing slip. He directed me to an 800 number, and option 3.
When I called, the rep had already received notice from Anthony (her supervisor) and said I'd have my corrected shipment within a week.
So, on the bright side, PM customer service cleaned up their mistake--and in an efficient manner, considering their likely perplexed-ness over our concern over such small of a detail!
-Tim