This office has many employees with enough miles on single carriers for free trips, but these miles have been difficult to use because few seats have been available when employees have needed to travel.
The office provided the employees with their miles. 
mnli hypothesis: The office provided the employees with their miles.  premise: This office has many employees with enough miles on single carriers for free trips, but these miles have been difficult to use because few seats have been available when employees have needed to travel.