The submit button ought to send an e-mail to whatever you have set as its destination. If it doesn't you should ask for help in the template support thread.
The "Contact Us" tab does link to the contact page, but most if not all of the links there shunt back to the down for maintenance page. You could disable the tab link by finding the megamenu file where this HTML is built:
HTML Code:
<li class="contactus-li" ><a href="http://www.petluxuryboutique.com/shop/contact_us" class="drop">Contact Us</a><!-- bof contact form -->
and commenting out the destination like this:
HTML Code:
<li class="contactus-li" ><a href="<!--http://www.petluxuryboutique.com/shop/contact_us-->" class="drop">Contact Us</a><!-- bof contact form -->