Ha, I know Carelon! It's their pharmacy division for specialty (read: expensive) medication. Not a clue as to why they'd be involved in a CPAP claim, but this story does ring far too close to home.
I once spent months fighting United Healthcare to stop hounding me for a $2k bill that I categorically did not owe. Countless phone reps were unable to remove it from my account; I only solved the problem by making a big enough stink on Twitter for someone from corporate to get involved. Good times!