You bought new licenses and added them but the new count is not added to the old count. The license window either still shows the old amount or it only shows the new amount.
You may see an error indicating that the licenses you are trying to apply have the same date as the existing licenses. (If this is the case, you need to contact Technical Support and apply licenses that have a later date than the existing licenses.)
In some cases, we cannot add the license count.
You will want to contact licensing and have your licenses combined. If you are not sure how to do it, please contact Customer Care.
Otherwise you can do that manually here at the Symantec Licensing Portal: https://licensing.symantec.com/acctmgmt/index.jsp?clearForm=true
Once you get the new license file, you will want to remove the old licenses via the License Removal tool: http://www.symantec.com/docs/HOWTO9437
Then add your combined license.
This document covers NS6 and NS7 licensing