SQL View Script Update

[GingaNinga]

Hello - I am in need of help to update a SQL View Script.
Basically, the condition in bold below is no longer required, and it is returning a value of 0, where I would expect a value greater than 0, based on what is highlighted in red.

I have tried to change the "WHEN" clause to point to the CustFrequency, and CustDuration fields respectively, however when I do that, my Sum of Hours still returns 0, for all (not just where the condition matches FT

I have also tried to comment out the entire "CASE" clause in bold - but Sum of Hours still returned 0.

Any help is greatly appreciated.

SELECT    ID
        ,Customer_ID
        ,Customer_ID_S
        ,Customer_ID_S+'|'+TerritoryID AS Customer_ID_S_Territory
        ,Store
        ,CustomerName2
        ,CustomerAddress1
        ,CustomerAddress2
        ,CustomerCity
        ,CustomerZipCode
--        ,CustomerCountry
        ,Prov
        ,CustomerPhone
        ,CustomerMobile 
        ,CustomerFax
        ,CustomerEmail
        ,CusLatitude 
        ,CusLongitude
        ,CustomerCL1
        ,Channel
        ,Banner
        ,[Regional Banner]
        ,VisitFrequency
        ,TerritoryID
        ,CustSTTReserved
        ,CustDuration
        ,CustSTNReserved
        ,CustFrequency
        ,CustSTNReserved2
        ,SalesTeam_ID_fromCust
        ,IsDistributor
        ,CAST(Duration as int) AS Duration
        ,CAST(Frequency as int) AS Frequency
[COLOR=rgb(209, 72, 65)]        ,CAST((Frequency*Duration + Frequency*15)/12/60 AS decimal(10,5)) AS [Sum of Hours][/COLOR]
        ,[Full Address]
        ,'Canada' AS CustomerCountry
FROM    (    SELECT    ID
                    ,cust1.Customer_ID
                    ,cust1.Customer_ID_S
                    ,Store
                    ,CustomerName2
                    ,CustomerAddress1
                    ,CustomerAddress2
                    ,CustomerCity
                    ,CustomerZipCode
                    ,CustomerCountry
                    ,Prov
                    ,CustomerPhone
                    ,CustomerMobile 
                    ,CustomerFax
                    ,CustomerEmail
                    ,CusLatitude 
                    ,CusLongitude
                    ,CustomerCL1
                    ,Channel
                    ,Banner
                    ,[Regional Banner]
                    ,VisitFrequency
                    ,terr.Territory_ID AS TerritoryID        --2020-04-22: pulling Territory ID from Customer to Territory table instead
                    ,CustSTTReserved
                    ,CustDuration
                    ,CustSTNReserved
                    ,CustFrequency
                    ,CustSTNReserved2
                    ,SalesTeam_ID_fromCust
                    ,IsDistributor
                    ,[Full Address]
                   [B] ,CASE    WHEN LEFT(terr.Territory_ID,1) = 'C' AND RIGHT(terr.Territory_ID,2)='FT'
                                    THEN CustSTNReserved
                                    ELSE CustDuration
                                    END AS Duration
                            ,CASE    WHEN LEFT(terr.Territory_ID,1) = 'C' AND RIGHT(terr.Territory_ID,2)='FT'
                                    THEN CustSTNReserved2
                                    ELSE CustFrequency
                                    END AS Frequency[/B]
            FROM        [CA_PowerBI].[dbo].[v_AFS_Customers]            cust1                    
            LEFT JOIN    [CA_PowerBI].[dbo].[v_AFS_CustomerToTerritory]    terr
            ON            cust1.Customer_ID_S=terr.Customer_ID_S)                cust2

GO

 

[GingaNinga]

Simplified version:
Looking to understand why the calculation ",CAST((CustFrequency*CustDuration+CustFrequency*15)/12/60 AS decimal(10,5)) AS [Sum of Hours]" in the below query does not return expected values, it is returning 0

SELECT    ID
        ,Cust1.Customer_ID
        ,Cust1.Customer_ID_S
        ,Cust1.Customer_ID_S+'|'+Terr.Territory_ID AS Customer_ID_S_Territory
        ,Store
        ,CustomerName2
        ,CustomerAddress1
        ,CustomerAddress2
        ,CustomerCity
        ,CustomerZipCode
--        ,CustomerCountry
        ,Prov
        ,CustomerPhone
        ,CustomerMobile 
        ,CustomerFax
        ,CustomerEmail
        ,CusLatitude 
        ,CusLongitude
        ,CustomerCL1
        ,Channel
        ,Banner
        ,[Regional Banner]
        ,VisitFrequency
        ,terr.Territory_ID
        ,CustSTTReserved
        ,CAST(CustDuration as int) as Duration
--        ,CustSTNReserved
        ,CAST(CustFrequency as int) as Frequency
--        ,CustSTNReserved2
        ,SalesTeam_ID_fromCust
        ,IsDistributor
        ,CAST((CustFrequency*CustDuration+CustFrequency*15)/12/60 AS decimal(10,5)) AS [Sum of Hours]
FROM        [CA_PowerBI].[dbo].[v_AFS_Customers]            cust1                    
            LEFT JOIN    [CA_PowerBI].[dbo].[v_AFS_CustomerToTerritory]    terr
            ON            cust1.Customer_ID_S=terr.Customer_ID_S