John never includes the proper documentation when submitting his requests to accounting. Sam at shipping never answers the phone from customer service reps who are dealing with unhappy clients about not getting their delivery. Diana never pitches in to help when her coworkers are overloaded.
Undoubtedly the most neglected aspect of customer service is internal customer service. It's unfortunate, because it plays a crucial role in an organization's ability to deliver outstanding service to its external customers.