Getting wrong result in sqlserver : I have two tables first one <pre>Fee_Payable_to_Students</pre> and another one <pre>Fee_Assign_Waiver_to_Students</pre>

it contains value as 
<pre>Fee_Payable_to_Students</pre>
<pre>
f_co |S_Adm_No | apr | may | june | jul | aug | sep | oct | nov | dec | jan | feb | mar
1    |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5
2    |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5

</pre>

<pre>Fee_Assign_Waiver_to_Students</pre>
<pre>
f_co|S_Adm_No | apr | may | june | jul | aug | sep | oct | nov | dec | jan | feb | mar
1   |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5
</pre>

I want to view my result as 

<pre>
S_Adm_No | Installment                                      | Amount  |Payable_Date
s_1	 |Quarter-1 (April, May &amp; June)	                    |  5      |Apr 15, 2018
s_1	 |Quarter-2 (July, August &amp; September)	            |  5      |Jul 15, 2018
s_1	 |Quarter-3 (October, November &amp; December)	    |  5      |Oct 15, 2018
s_1	 |Quarter-4 (January, February &amp; March)	            |  5      |Jan 15, 2019

</pre>

my sql query is here................




<pre>BEGIN
		SELECT unPvt.S_Adm_No, Installment, 
		sum(Amount) AS Amount, CASE 
		
		WHEN  Installment = 'Quarter-1 (April, May &amp; June)' THEN 'Apr 15, 2018'		
		WHEN  Installment = 'Quarter-2 (July, August &amp; September)' THEN 'Jul 15, 2018'		
		WHEN  Installment = 'Quarter-3 (October, November &amp; December)' THEN 'Oct 15, 2018'		
		WHEN  Installment = 'Quarter-4 (January, February &amp; March)' THEN 'Jan 15, 2019' END AS Payable_Date 
			
		FROM (	SELECT pc.S_Adm_No,
				(Apr + May + Jun)-COALESCE(CON.Qa1,0) AS [Quarter-1 (April, May &amp; June)], 	
				(Jul + Aug + Sep)-COALESCE(CON.Qa2,0) AS [Quarter-2 (July, August &amp; September)], 	
				(Oct + Nov + Dec)-COALESCE(CON.Qa3,0) AS [Quarter-3 (October, November &amp; December)], 	
				(Jan + Feb + Mar)-COALESCE(CON.Qa4,0) AS [Quarter-4 (January, February &amp; March)]	
		FROM Fee_Payable_to_Students pc
		
		LEFT JOIN
			(
				SELECT S_Adm_no,
				sum(E_Apr+E_May+E_Jun) Qa1, 
				sum(E_Jul+E_Aug+E_Sep) Qa2,
				sum(E_Oct+E_Nov+E_Dec) Qa3, 
				sum(E_Jan+E_Feb+E_Mar) Qa4
				FROM Fee_Assign_Waiver_to_Students w
				group by S_Adm_No
			)	AS CON ON pc.S_Adm_no = CON.S_Adm_no
					where pc.S_Adm_No=s_1) AS Pvt UNPIVOT 
					(Amount FOR Installment IN 
										([Quarter-1 (April, May &amp; June)], 
										[Quarter-2 (July, August &amp; September)], 
										[Quarter-3 (October, November &amp; December)], 
										[Quarter-4 (January, February &amp; March)])) AS unPvt 
			GROUP BY unPvt.S_Adm_No,unPvt.Installment</pre>