3.3.2 Should you wish to change any aspect of your transportation you must contact us in advance. The fare for your new transportation will be calculated and you will be given the option of accepting the new price or maintaining your original transportation as ticketed. Should you be required to change any aspect of your transportation due to force Majeure. You must contact us as soon as practicable and we will use reasonable efforts to transport you to your next stopper or final destination, without recalculation of the fare.
3.3.3. Should you change your transportation without our agreement, we will assess the correct price for your actual travel. You will have to pay any difference between the price you have paid and the total price applicable for your revised transportations. We will refund you the difference if the new price is lower but otherwise, your unmissed Coupons have no value.
3.3.4 Please be aware that while some types of changes will not result in a change of fare, others, such as changing the place of departure (for example if you do not fly the first segment) or reversing the direction you travel, can result in an increase in price. Many fares are valid only on the dates and for the flights shown on the ticket and may not be changed at all, or only upon payment of an additional fee.
3.3.5 Each Flight Coupon contained in your Ticket will be accepted for transportation in the class of service on the date and flight for which space has been reserved. When a Ticket is originally issued without a reservation being specified, space may be later reserved subject to our tariff and the availability of space on the flight requested.
3.3.6 Please be advised that in the event you do not show up for any flight without advising us in advance, we may cancel your return or onward reservations. However, if you do advise us in advance, we will not cancel your subsequent flight reservation".
Delta Ruling Number 19777-06-1409 Sep 2015