Hello, @Noely2 . It is a little unclear from your posting if you followed the claim steps outlined by Air BNB, i.e., develop proof of damage and cost of damage; contact guest prior to another guest coming in; if no response or denial of responsibility, contact Air BNB with the said proof. Air BNB reaches out to the guest and also obtains response. If denial by guest but the pictures or other proof is convincing, then Air BNB determines the value of the damages and seeks payment from the guest method of payment.
If you did that and still got a denial and closed case, contact again. There are many discussion threads that attest to persistence works. However, if you did not take the appropriate steps, you may have a problem. As you know, there is no real security deposit, only an amount defined by the host that the guest agrees is available if there is a valid claim. Air BNB then accesses the payment method.