Why doesn't PMG differentiate between Pick sub-letters?

I'm putting together a complete set of notes from Aruba.  PMG has the 1986, 1990, 1993 & 2003 notes in place.  After that, nothing though Aruba issued notes in 2008 (Pick b series from 2003) and 2012 (Pick c series from 2003) and a brand new unlisted series that just came out.  I'd like those notes individually added for the complete set.  I've asked for a Basic Set, Set with Varieties and a Complete Set with Varieties and Specimens.  Crickets.  Nothing.  Nada.  In fact, it's a challenge to get the "C Series" notes added.  I have to ask every time I want to add one as the set won't recognize it.

Anyone else experience this?  Any work arounds?  I really enjoyed how easy it was to use a not to be named out of business competitor's registry set system.

I look forward to all feedback.