Can't clear out an old activation even after deactivatingAnswered

We have a client who has a very secure computer and needs to activate offline.  They are connected to the internet but their VPN doesn't allow our app to activate via the internet.  Anyhow, they used the offline activation and it worked.  However, now they want to extend the license period.  We have an expire date in the features and extended that.  We have the license set up to allow deactivations by the user.  They tried to deactivate from turboactivate app and could not.  We have code in our app that will deactivate the license too.  That didn't work either.  Please advise on how they can get out of this endless loop and be able to reactivate the license offline.