Open the Delta Airlines official website in your web browser at www.delta.com.
You need to select "My Trips" from the menu at the top of the home page.
A get box that allows you to type your booking confirmation number, first and last names, and then click enter is required.
You can choose the trip you want to cancel on the following page by going to your booking and clicking "Modify Flight."
Perform the flight change or cancellation on the following step.
You may also contact us to request a Cancellation and refund.
Read more : Allegiant Air cancellation flight