@Jonny46 Sounds like you were dealt with very poorly and I hope you can get a successful resolution.
One thing I noticed in the first paragraph of your post is that you said your initial message to the host regarding when you would be checking in was never replied to and you didn't think anything of it at the time.
It's actually a red flag, both for hosts and guests, if their messages are ignored by the other party. Of course, you can't expect an immediate response since people can be at work or otherwise busy. But if a response isn't forthcoming within a day or so, that should alert you that this host may not be trustworthy or responsible. I can't imagine not responding to my guests' messages, even if it's just to acknowledge that I read it and all's okay. Seems like really sloppy hosting not to. Guests need to feel assured that all will be ready and the check-in will be smooth, especially when you have children in tow.
So in the future, if you don't get a response, message again asking if they got your message (sometimes there could actually be glitch where a message doesn't go through) and if you still don't get a response, you should contact Airbnb to see if they can make contact with the host. If they can't, I'd suggest asking them to cancel on your behalf and apply your payment to a different booking.
What was the check-in window listed on this place anyway?