Hello @Brenda122,
In the case where you've received the payment for a cancelled reservation and you issue a refund Airbnb usually handles that by deducting the value of the refund from your payment for the next guest to check in.
As they can't take the already paid out money back from you, and provided it wasn't taken from your credit card, the only option airbnb has is to deduct the amount from the next payment due to you.
You should contact Airbnb support to discuss it if the above doesn't account for your situation. You should also contact them to ensure that the guest hasn't received a double refund due to claiming extenuating circumstances.
Steve.