We were booked into a caravan in Cornwall for 7 nights but came home after 3 nights as the caravan was dreadful at the site owners (independent place, not a company like Parkdean) wouldn't move us as they disagreed anything was wrong. The mattresses were about 1 inch thick and you could feel the frame underneath, the window in the lounge didn't shut properly and let the cold air in (it was October), the shower didn't get hot and at best was tepid, toilet didn't flush properly, the carpets were absolutely filthy.
Came home on day 5 of a 2 week holiday in Orlando due to my uncle being in a serious car accident and we didn't think he'd survive (he did).