Sometime, it looks impossible to shrink the Trucated Log file. Following code always shrinks the Trucated Log File to minimum size possible.
This script should allow you to shrink a DB log file.
USE DatabaseName
GO
            DBCC SHRINKFILE(<TransactionLogName>, 1)
    BACKUP LOG <DatabaseName> WITH TRUNCATE_ONLY
            DBCC SHRINKFILE(<TransactionLogName>, 1)