So let me see if I understand the problem. A guest pays for s site for four Days but does not use the site. You want the site but cant' t have it because is in actuality reserved by someone else.
You have no idea what caused the guest to pay but not used the site, yet you are being critical.
Prime example, we just returned from a three month trip out west. The camper, being new needs some warranty work done. We occupied a site, to prepare the coach and bring it in to a dealership for repairs. We also have a home in town which was damage during some resent storms while we were away. we are getting the home and the camper ready which is time consuming when dealing with insurance companies. Point is you don't know what is going on people's life, so lighten up on the criticism .