Sub-menus not accessible to screen readers

Thanks for this great, easy to use plugin. I just found some accessibility issues, wondering if its a conflict with another plugin or my theme, or if this is part of the plugin itself.

We’ve had our menu tested by a blind user and he reported that he couldn’t access the submenus using any of his usual methods. I checked it myself and although it tabs beautifully with a keyboard, it does seem to have some issues when I use VoiceOver.

1) The menu item should have a roll of button (or be a button) and should support spacebar open?and closing it in addition to the return key. This element:

<a class=”mega-menu-link” tabindex=”0″ aria-haspopup=”true” aria-expanded=”false”>ABOUT US<span class=”mega-indicator” data-has-click-event=”true”></span></a>

2) When the menu is opened with the return key, the submenu does become visible, but nothing is announced to screen readers that the submenu opened.

3) All of the links have aria-haspopup=”true” aria-expanded=”false” on them, including the links in submenus that don’t have another submenu. This causes them to be read out as “Menu Popup Collapsed Link Our Team” instead of “Link Our Team”

4)Only one link with a submenu is described as “List, 6 items” (the first one, About Us). The 3 other submenus are not

The page I need help with: [log in to see the link]