You have the option of selling your ticket back to them and getting your money back directly into your bank account via the credit card you used to pay. All you have to do is go to the Shotgun application and click on the ticket you want to resell. On top of it, you will see the option "Resell" and then "Private resale".
Next, you will need to enter the name, phone number, or email address connected to the recipient's Shotgun account, and the recipient will receive an email or text message with a link that will take them to payment. Once payment is complete, the new buyer will find their ticket in their Shotgun account, and you will be refunded with an invalid (and greyed out) ticket in your account.