After 9 pm there is no reception and you need to do the check in via an automated system. BUT, the only reservation number I had was from Hotels.com, which of course was not their own reservation number. Tried to call their helpline, no pick up. Tried to call Hotels.com and no pick up. (Anyway, if Hotels.com could not help, there was nobody at reception)
Ended up "paying" for another room and in the morning, the very unfriendly reception person told me that they would still charge me for the room booked via Hotels.com So, I ended up paying twice for a room that is not even worth once. Dreadful hotel, avoid at any costs