Comment box and admin screen option

Hi,
I am using Promotion Slider in my site http://www.khursani.com without any issue. But comment form is not displaying and it says ‘comments are closed’. I also don’t see the ‘Discussion’ menu in Admin dashboard ‘Screen options’. Any help please.
Thanks in advance.
Etchbee

http://ww.wp.xz.cn/extend/plugins/promotion-slider/