I'm afraid your technical support is correct, if they keys (password or certificate) have been lost, then the data is lost.
If you have any documentation on your GE implemenation you can check to see if the Master Recovery Certificate option was used, and see if this has been archived anywhere (assuming we are talking about Removable Storage Encryption here).
Other than that, you might try logging a case with Symantec: http://www.symantec.com/support/techsupp_contact_phone.jsp