Hi,
In that case you can try the bellow query
SELECT a.dt, COUNT(*) As Customer_Count
FROM
(
SELECT MIN(Convert(varchar,dateTimeStamp,101)) AS dt, CUS.customerName, CUS.CustomerID
FROM EasyRecharge.dbo.CustomerUsage CUS
INNER JOIN EasyRecharge.dbo.Customers_Dormant CNU on CUS.FromMSISDN = CNU.MSISDN
WHERE ([DateTimeStamp]
between '2009/07/01 00:00:00' AND '2009/07/08 23:59:59')
GROUP BY CUS.customerName, CUS.customerID
) A
GROUP BY a.dt