I want to eliminate Null value from the output.

I have already used below technique for my query but still problem is not solved.

SET ANSI_WARNINGS OFF;**
SUM(CASE WHEN [qty] IS NULL THEN 0 ELSE qty END) AS [qty]

Here's my query

SET ANSI_WARNINGS ON;
DECLARE @cols nvarchar(max),
                        @query nvarchar(max),

                @Date DATETIME
                SET @Date = DATEADD(mm, -6, CURRENT_TIMESTAMP);

                WITH cte AS 
                        ( 
                        SELECT 0 AS TheMonth  
                        UNION ALL  
                        SELECT TheMonth + 1 
                        FROM cte 
                        WHERE TheMonth < 5 
                        )

                SELECT TheMonth
                INTO #temp
                FROM cte

SELECT @cols =   STUFF((SELECT distinct ',' + QUOTENAME(A.warehouse_name) 
                                 from RS_Company_Warehouse_Master a    
                                 FOR XML PATH(''), TYPE 
                                 ).value('.', 'NVARCHAR(MAX)') 
                                 ,1,1,'') 
SET ANSI_WARNINGS OFF;
SELECT @query = 'SELECT                  
                 LEFT(DATENAME(MONTH,DATEADD(MONTH,TheMonth -6 + 1,GETDATE())),3) AS [month], 
                 DATEPART(YEAR,DATEADD(MONTH,TheMonth - 6 + 1 ,GETDATE())) AS [year], 
                 '+@cols+'
                 from
                 (
                 SELECT 
                 TheMonth,                
                 SUM(CASE WHEN [qty] IS NULL THEN 0 ELSE qty END) AS [qty],
                 warehouse_name
                 FROM 
                 #temp
                 LEFT OUTER JOIN RS_Sell_Order_Master AS SM ON invoice_date >= DATEADD(MM, TheMonth, '''+convert(varchar(10), @Date, 120)+''')           
                                                            AND invoice_date < DATEADD(MM, TheMonth + 1, '''+convert(varchar(10), @Date, 120)+''')                                                                                                                                                
                 LEFT OUTER JOIN RS_Company_Warehouse_Master AS CWM ON CWM.c_warehouse_id = SM.c_warehouse_id
                 LEFT OUTER JOIN RS_Sells_Invoice_Info_Master AS SIIM ON SIIM.sell_order_no = SM.sell_order_no
                 GROUP BY 
                 CWM.warehouse_name,
                 TheMonth
                 ) as a
                 PIVOT
                 (
                    sum(qty) for warehouse_name
                    IN ('+@cols+')
                 ) AS P
                 '
                 execute sp_executesql @query;
                 DROP TABLE #temp

Output: