SUM case in SQL Server

SELECT
CONVERT(NVARCHAR(30),TDate,106) AS 'DATE',
COUNT(*) AS 'TOTAL RECEIVED',
SUM(CASE WHEN Attempt != 0 AND CallingDateTime IS NOT NULL THEN 1 ELSE 0 END)AS 'CALLED',
SUM(CASE WHEN Attempt = 0 AND CallingDateTime IS NULL AND AgentName IS NULL THEN 1 ELSE 0 END)AS 'PENDING',
SUM(CASE WHEN Attempt < 3 AND CallingDateTime IS NOT NULL AND ConnectedStatus IN('DID13','DID18','DID19','DID20','DID16') THEN 1 ELSE 0 END)AS 'RE-WORKABLE',
SUM(CASE WHEN CallingDateTime IS NOT NULL AND ConnectedStatus IN('DID8','DID9') THEN 1 ELSE 0 END)AS 'RE-SPOOLED'
FROM Cust_Feedback
WHERE
TDate BETWEEN @FDATE AND @TDATE
GROUP BY CONVERT(NVARCHAR(30),TDate,106)
ORDER BY CAST(CONVERT(NVARCHAR(30),TDate,106) AS DATETIME)