Style Manager > find style > edit templates > open the template "contactus" and add text:
HTML Code:
<tr>
<td class="panelsurround" align="center">
<div class="panel">
<div style="width:$stylevar[formwidth]" align="$stylevar[left]">
ADD TEXT HERE
<fieldset class="fieldset">
<legend>$vbphrase[your_details]</legend>
You can play with that and add the text in another area. That is just one possible area to add it.