Multiple Periodic Charges within a billing cycle - mysql

Question

Each department is supposed to have only one statement per monthly billing cycle.

My goal is to figure out how many departments have been hit with more than one billing statement (having a value greater than $0.00) within the same billing cycle.  

CONTEXT: 
My current query is set to check only departments that are supposed to be billed monthly.
Department table has a one-to-many relationship with Statement table (a department is expected to have one or more statements)
Statement table has a one-to-many relationship with Trans table (a statement is expected to have one or more transactions)
Each billing statement has its own statement_close_date
c.type=‘periodic’ refers to a bill that only occurs once per billing cycle
d.period=1 represents accounts that are billed monthly
s.status=‘closed’ represents only closed statements
d.exp_date represents billing expiration date
v.status=‘active’ and d.status=‘active’ are meant to ensure that only active departments are being queried.
I also tried searching between specific expire dates on a per account basis.

The problem with my query is that it outputs the total number of billing statement_close_dates with a value greater than $0.00, instead of only checking for multiple occurrences within a billing cycle. 

How can this query be modified to only output departments with more than one instance of a bill consisting of a periodic type charge greater than $0.00 within each department’s billing cycle?  

QUERY:
SELECT s.department_id, s.statement_id, COUNT(s.statement_close_date) AS sd,
t.trans_id, from_unixtime(s.statement_close_date)
FROM statement s
INNER JOIN trans t
ON t.statement_id=s.statement_id
INNER JOIN cde c
ON t.cde=c.cde
INNER JOIN department d
ON s.department_id=d.department_id
WHERE from_unixtime(s.statement_close_date) BETWEEN
DATE_SUB(from_unixtime(d.exp_date), INTERVAL 1 MONTH) AND
from_unixtime(d.exp_date)  
AND d.period=‘1’
AND s.status='closed'
AND t.dollars>0
AND c.type='periodic'
GROUP BY s.statement_id DESC
HAVING sd>1
SAMPLE OUTPUT:
department_id statement_id sd trans_id statement_close_date
1719712 9351464 3 98403043 2018-09-24
1719709 9351463 2 98403026 2018-09-24
1719708 9351462 2 98403010 2018-09-24
1719665 9351457 3 97374764 2018-09-24