You need to nest inside a row i.e.
<div class="row">
<div class="breadcrumbs small-12 columns">
My account / Companies list /
<div class="row">
<div class="Heading-container small-6 columns">
<h1>Create new company</h1>
</div>
</div> <!--/nested row-->
</div>
</div><!--/row-->