I've traveled quite a bit, including to Barcelona. If you speak English (and this person clearly does) then "don't speak the language" is not an issue there, or indeed almost anywhere.
If I book a place for a certain period, then I'm staying for that whole period. If the host suddenly changes their mind and tells me I have to move, no way. I'm contacting the booking agency and having them tell the host to get lost. If the booking agency doesn't help then I'm initiating a chargeback and finding a hotel. At no point is it reasonable to just pack up, hop into a complete stranger's car at their insistence, and be driven off to some place where they won't even tell you where you're going.
Traveling used to be pretty interesting when things went wrong. I got stranded in the Beijing airport once with only a rudimentary command of Mandarin because the airline canceled my flight and never told me, and I had to hunt down an airline employee, borrow a phone so I could contact people, etc. But now? Bring a smartphone and you're a few taps away from communicating with anybody you need. Host is being obstinate? Call AirBnB. Still doesn't work? Book a new place. You make a mistake taking a car with a stranger and he takes you to a place where you don't even know where it is? Open up a maps app and find out where you are. Can't talk to people? Google Translate to the rescue.
You better believe that if the host refuses to honor our agreement and starts trying to jerk me around, I'm going to blow them off and sit with my luggage in the street while I resolve the problem myself. Relying on strangers to fix your problems, when said strangers have already demonstrated that they don't really care about you, is setting yourself up to be a victim.