Hmmm I see, thats a brainier.
So let say for this example we change the N-Co date to prior 27th.

CREATE TABLE #temp
(
Identifier varchar(20)NOT NULL
,CreatedDate DATETIME NOT NULL
,CompletedDate DATETIME NOT NULL
,SN_Type varchar(20) NOT NULL
,SN_Status varchar(20) NOT NULL
)
;

INSERT INTO #temp
VALUES('64074558792','20160729','20160805','Re-Activattion','SENT');
INSERT INTO #temp
VALUES('64074558792','20160810','20160810','Re-Activattion','N-CO');
INSERT INTO #temp
VALUES('64074558792','20160812','20160812','Re-Activattion','N-CO');
INSERT INTO #temp
VALUES('64074558792','20160811','20160811','Re-Activattion','COMP');
INSERT INTO #temp
VALUES('64074558792','20160811','20160813','Re-Activattion','N-CO');
INSERT INTO #temp
VALUES ('61030203647','20160427','20160427','Re-Activattion', 'COMP');
INSERT INTO #temp
VALUES('61030203647','20160425','20160426','Re-Activattion', 'N-CO');
INSERT INTO #temp
VALUES('61030203647','20160422','20160422','Re-Activattion', 'N-CO');
INSERT INTO #temp
VALUES('61030203647','20170210','20170210','Re-Activattion', 'COMP');
INSERT INTO #temp
VALUES('61030203688','20170409','20170210','Re-Activattion', 'SENT');
INSERT INTO #temp
VALUES('61030203699','20170409','20170210','De-Activattion', 'COMP');
;