My license states that it was used for a website I previously owned. I did have someone try it out on the domain, but did not end up using it. Can the license be reset since it was never formally used? If so, how?
To use purchase code again which already used for any website (mean theme license already registered) you have to unregister/deactivate the theme license from the old domain/website. you can not use the same purchase code (license) for more than 1 website.
contact the theme Author and let them know How to Contact your purchased theme Author, the theme author will be happy to assist you within their scope.