Hi Guys
Came across this thread but after I had fixed the same problem.
You need to go to the template folder (jf-calla-exteriors)/html/com_contact/contact/default_form.php-
insert these few lines just before the bits about contact_message
<div class="control-group">
<div class="control-label"><?php echo $this->form->getLabel('contact_subject'); ?></div>
<div class="controls"><?php echo $this->form->getInput('contact_subject'); ?></div>
</div>