Fix validation error in Contact Form 7

I have a contact client that uses Wordpress, and on one of the pages they have a Contact 7 orderform. The problem is that field validation doesn't really work. Although there are some mandatory fields, that also get flagged as being mandatory, the form is being send and the visitor sees the thank-you-page. However, the form never reaches my client. So, I need help to make sure that the form doesn't go away until all fields have been properly filled out and validated. You can see the form here: [login to view URL]ä[login to view URL] Mind the Swedish character "ä" in the url.