www.auran.com/helpdesk - alternatively you could just post your question on the forum. Unless it's an admin / serial number query then there's a 99% chance someone will be able to help or will know the answer.
Also, realize that there's only 3 employees working on the Trainz crew right now, so you're probably going to have to have a little patience. I'm sure they'll get to your request as soon as they can.