I worte a review about this hotel a few months back, where I had already mentioned this problem: We arrived without a reservation and tried to get a room. It was 7:00 am and the staff told us to wait because "most likely" one would become free around 12:00, but they couldn't be 100 percent sure. This was already strange, but we decided to wait. I think they know VERY well who is checking out and if they have other reservations that will fill them up again. They told us the restaurant is a nice place to wait. So we waited and waited and waited (by the way, the staff at the restaurant are EXTREMELY SLOW) and at the end they just smiled and said sorry, no rooms free.
But this is not the worst part, a couple came after us, just as we were leaving, Later we met them by chance in the city center and they told us they didn't have a reservation...they were just given a room straight away. I think the owner might not now what his staff are doing. I don't doubt he is honest, but the staff seems to have their own rules. But it is still a very bad way to treat travelers.