UPS is being UPS here.
They’re abandoning packages, then sending her a bill for COD as if she accepted the package but didn’t pay.
The fact that if she digs in and fights it she can eventually dispute each charge is somewhat separate from UPS and their collections contractors harassing her about the ‘debt’, or the new packages that keep showing up.
I remember the G4 with great fondness; my dad’s G4 was what I did homework and gamed on as a highschooler, and then when he retired it I brought it to college and it served as our living room ‘jukebox’ for another five years.