RULE 240: FLIGHT DELAYS/CANCELLATIONS
C. Schedule Changes, Delays, & Flight Cancellations within Delta’s Control
When, as a result of factors within Delta’s control, you miss a connection due to flight delays, your flight is cancelled, or a substitution of equipment results in a change in the class of service that you purchased or prevents us from transporting you, Delta will provide you with the following:
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2. Full or Partial Refund
If some or all of your ticket is unused, you may be entitled to a refund. Any refunds will be made as provided in Rule 260.

RULE 260: INVOLUNTARY REFUNDS
A) The amount carrier will refund upon surrender of the unused portion of the passenger's tickets pursuant to rules 35 (refusal to transport), 50 (acceptance of children), or 240 (flight delays/cancellations) will be:
1) If no portion of the ticket has been used the refund will be an amount equal to the fare paid.
2) If a portion of the ticket has been used and termination (interruption) occurs:
a) At A Fare Breakpoint - The refund will be an amount equal to the fare paid for the unused transportation from the point of termination (interruption) to the destination or next stopover point named on the ticket, or to a point at which transportation is to be resumed. No refund will apply when alternate transportation is provided by Delta and accepted by the passenger.
b) Within A Fare Component - The refund will be an amount equal to the percentage of unflown mileage to fare component mileage by prorating the fare paid for the fare component, from the point of termination/interruption to the destination, or next stopover point named on the ticket, or to the point at which transportation is to be resumed. No refund will apply when alternate transportation is provided by Delta and accepted by the passenger.
B) Notwithstanding the provisions of this rule Delta will not accept for any purposes under this rule passenger tickets or related transportation documents issued by any carrier which is in substantial default of its interline obligations or which voluntarily or involuntarily has become the subject of bankruptcy proceedings.