It's actually not that easy to get the ticket. The ticket is not just a ticket that you can but at a machine whenever you want, it's actually a subscription that at the moment can only be started at the beginning of the month and the request must be received something like 4 days before the end of the month, otherwise you slip to the next month. I'm not sure if there are additional conditions not covered here but I can imagine there are are lots of other quirks.