How can we restrict or reserve one LANPAK from one IP address.

We have a web store where we selling items . a customer purchases item on web store and it goes and creates an order and an invoice in sage.. The service  is  configured to use a sage LANPAK. Our issue is during month end all users are logged into sage and the service fails to create an order and an invoice by stating below message.

“Before Session Creation::Session Initialized, You have reached the maximum number of concurrent users for your LanPak license.”

When month end is not near there are no issues since few lan pak are  available for the service to consume and make a  transaction successful.  

Kentico and .net  has been used.

Is there a workaround/solution  for this.  Please assist.