Hi Kym,
Are you speaking about property within the maritime zone – i.e. beachfront? Such property has restrictions on foreign ownership and concessions are usually not transferable. Concessions are kind of like leases with the government and are granted on a long-term but temporary basis.
But I’m not an attorney – so I would suggest contacting a local lawyer experienced in real estate to help you with this issue. They can look up the property and figure out what’s going on.
But right now, you can review the status of a property in the Registro Nacional/National Registry:
http://www.rnpdigital.com/index.htm
Roger Petersen’s law firm (they speak at IL conferences) has a great guide to using this online database here:http://www.costaricalaw.com/Real-Estate-and-Property-Law/costa-rica-online-access-to-public-records-at-the-national-registry.html