DFAS can take some time to answer or even not answer at all. But they might also not have any slot available for new students, or only on very short notice after potential student's cancellations.
You can expect them to be fully booked until beginning of 2018, but if you want to be 100% sure you would have to call them a few times.
It's a small school, they don't have secretaries to answer all your calls and emails.