Why bother reading the contract when it's faster to just post something? See Rule 3 cut & pasted. 180 degrees opposite from what you wrote. How does that help anybody?

RULE 3: SCHEDULES AND OPERATIONS


Delta will use its best efforts to carry the passenger and baggage with reasonable dispatch. Times
shown in timetables or elsewhere are not guaranteed and form no part of this contract. Delta may
without notice substitute alternate carriers or aircraft, and may alter or omit stopping places
shown on the ticket in case of necessity. Schedules are subject to change without notice. Delta is
not responsible or liable for making connections, or for failing to operate any
flight according to schedule, or for changing the schedule or any flight.