Windows Service not stopping in Windows Server 2012 but easily on Windows 7

Question

I have a below script which is attached to a windows service on stop command:-

wmic service where name='%NS_SERVICE_NAME%' get ProcessId | more +1 > tmp.txt
set /p NS_PID=<tmp.txt
del tmp.txt
for /f %%i in ('wmic process where "(ParentProcessId=%NS_PID%)" get ProcessId ^| more +1') do (
    for /f %%a in ('wmic process where "(ParentProcessId=%%i)" get ProcessId ^| more +1') do (
        echo %%a|findstr "^[-][1-9][0-9]*$ ^[1-9][0-9]*$ ^0$">nul && TASKKILL /F /PID %%a || rem
        IF %ERRORLEVEL% NEQ 0 do (
           exit
        )
    )
)

which works fine on Windows 7 and service stops quickly in 1-2 seconds, but in case of Windows Server 2012 the service does not stop and keeps in stopping state unless the process related to it is ended.

The error which I get in logs is as below:- "No Instance(s) Available."

Can some one help me in this regard.