You should not have gone to the property prior to your reservation. If you had concerns about the host not answering your messages you should call airbnb, not go to the property.
I would not be happy if a guest showed up before the reservation date.
How long ago did you try to contact the host? I recently read a post where a guest contacted the host and wanted to contact airbnb because it had already been one hour and the host was not responding. You need to give a couple of days, some hosts don't acess their messages often. Did you try calling?