Last updated: 2018-05-17

Source: https://support.freshdesk.com/support/solutions/articles/233255-how-can-i-delete-an-archived-ticket-

In order to delete an archived ticket, please go to the corresponding ticket page (either by performing a Search or hitting the ticket ID directly in the URL). Here, you will find the ' Delete forever' button. Clicking on this button will permanently delete the ticket from the helpdesk.

This option is only available on Freshdesk Mint.