The way airbnb works is you need to give the guest 72 hours to resolve the issue themselves. Sometimes people will own up and sometimes they don't. Which I really don't get.... After the 72 you escalate it to airbnb. Of course, this is where the wait really begins. It is important that you always back things with pics if you want to be reimbursed.
I used the phone numbers that I just gave you and had it resolved within 24 hours after I contacted them.
I have never had airbnb come back and tell me that they would not resolve an issue when we have requested help!
Try calling them! If people keep complaining, they'll eventually get the idea!