I think they are going to say they are only responsible for the equipment not the incidentals. You can always try though. Its sort of like when a computer fails or a camera goes bad...they are not responsible for the content. Some people will probably tell you that you should have checked it at home first but working today does not guarantee it will work tomorrow.
Two years ago we almost had to leave a campground because of AC issues. It was 105 degrees and no air and two dogs. Turned out it was a brownout that kept popping the circuit. Thankfully a couple hours later the temps lowered enough that there was enough electricity to go around and never had the issue pop p again that weekend. I don't think it was the campgrounds fault....the next day was just as hot and the AC worked.
Sorry you lost that family time.