This is a host and guest forum not monitored by Airbnb @Stuart94 they won't see your comment 🙂
Sorry you have had a difficult experience but it's not at all clear what happened.
From what I can gather a guest broke your window, you presumably contacted the guest for payment, they ignored/refused, then you applied under the guarantee. Did I understand correctly.
I presume you followed the procedure they lay down for claims, as you say you had a claim last year.
So yes it is more than annoying that your case manager ignored your email and then you had to call multiple times, but I don't understand why that would mean they would close down your case.
Could you give more detail?
Unfortunately when you claim guests can lead negative reviews. But of course you can leave your own to warn hosts of their behaviour and respond and make it clear the guest raised no issues during their stay and only left a negative review after you put in a claim because they broke your window
If all your other reviews are positive other guests will soon see through this.