@Abdullah-R-0
I see...if there were other guests complaining that changes the situation. I would try again to get the review removed. Provide screen shots of the other guests complaints and your proof of house rule violations again. I would not call Airbnb but use the chat feature so there is a written record.
Did you charge for the unregistered guests? Did the guest staying pay it? If so, they have admitted they broke the house rules. If they didn't pay, and you don't have anything in your house rules stating there is a fee for unregistered guests, then I don't believe Airbnb will help you on that one.
I think there is also something like the guest has to provide proof of an issue within 72 hours? (not sure about the time frame) after check-out. If they didn't complain within that window, it's no valid. For example: guest complains 5days after checkout that they developed reaction to bed bugs. That is outside the reporting window and should not be honored as far as refunds go. I think the review would still stand however.
For now, I would post a public response (non-emotional and factual) that points out the guest posted a negative review after they brought in unregistered guests against house rules and whatever else they did. Keep it short. That way other guests can read between the lines.