You must send a private message to one of the volunteers with the following information:
Username and ID
The reason for opening a ticket (Lost Auth)
E-mail associated with the account
Mention if you still have access to this e-mail
Then a ticket will be opened for you. You must send your message in english.
Go to http://forum.xat.com/staff, choose one of the volunteers and click on the "Message" button to send a private message.
And also, if you want to check the response times of the departments look at the article http://xat.wiki/Ticket_times