DiskCatalogMaker is a shareware. You can try the app free for 30 days. Please evaluate it before you buy it.
If you have purchased the wrong item, please send a refund request to firstname.lastname@example.org within 14 days. It will take some time to process it and revoke the license number.
If you have purchased it via Mac App Store, please send a refund request to Apple. You can contact Apple by going to the following link: http://www.apple.com/support/mac/app-store/ (There, click on the Account and Billing button in Contact Support and request a refund. Please be specific about why you request the refund.)