@Susan896 Bringing too many guests by want-to-be, slick artists is probably the most common hassle hosts face. Collecting from the culprits is probably the 2nd worst ordeal. Getting Airbnb involved is probably the riskiest approach to take.
Solution (applicable only in the future): Prevent it from happening in the first place, if you can help it. You have proof is happening, address the situation on the spot, in the most friendliest of ways; there may be an amicable compromise depending on who you are dealing with.