Wordpress website mobilw-menu main points doesn't link to sites

I have a problem with the mobile menu on my wordpress website. It's this site: http://ift.tt/1zSZ4mu

If you make your viewport smaller, so that the mobile navigation button shows up, you can click it and the mobile menu shows up.

My problem is following: If I click on the main points in the navigation (like IT-Service, Reparatur or Unternehmen) nothing happens. But I would this main points like to open the sites, which are liked to them. In the Desktop Navigation it works perfect. If I click on "Reparatur", http://ift.tt/1EXv7Ar this links opens, if I click on IT-Service, http://ift.tt/1zSZ4mw this link opens, and so on... On mobile nothing happens if I click them.

I modified the navigation like to display all of the links of the navigation at the same time. Prior the sublinks showed up in a dropdown, if i clicked on one of the mainpoints, but i didn't want this "feature".

So I know, that there is a javascript, that handles that but I don't know which one it is or what I have to change to make the main points link to their pages.

Maybe one of you guys can help me?

Greetings, Linda