We arrived late, and the room we were shown ("superior") was incredibly small had no window. It had an opening onto an interior airshaft. We paid for an upgrade to a "corner room." This had 2 windows over the street, but was also very small (the desk chair could not be pulled out from under the desk without hitting the bed). As it was very late, we just went to bed---but the room stank of an open toilet. It was not the bathroom in the room. The smell was coming from the wall directly behind the bed. We had to sleep with a window open. As well, the bed was smaller (not king) than advertised and the pillows were those very hard bags of what felt like towels. When we spoke to the staff first thing in the morning, they said "oh, well, when it rains in Valencia, every place smells like that. My apartment smells like that. It is just the way things are." Then they came up to the room and sniffed the air. "We don not smell anything. And we have no other room for you."
We immediately checked out and went to a different (and much better) hotel. When we asked for a refund of the unused 4 nights, they sent an email saying "We did not smell anything, and you paid in advance, so NO REFUND."
The day manager, the restaurant manager (waitperson?), the housekeeping manager were all completely uninterested in addressing the issue or even really listening. They said "send an email to the website. They should get back to you in a day or two." never heard a word.