Can I cancel my Delta flight and get a refund ?

You are permitted to cancel a ticket in accordance with Delta Airlines cancellation policy under the following conditions:

You can change your mind within 24 hours after purchasing your ticket directly from Delta.
A 1.5-hour delay or cancellation has been made to your Delta flight.
Your admission is totally transferable.
A death occurs in your reservation.
You revoke an elite status reward ticket.
You receive a military deployment order.
Delta accepts your request to cancel when an emergency arises.

Check also : Allegiant Air cancellation policy