diegoasc
It seems that you use editor when modifying the content of article which strips out HTML tags - this is a known issue in Joomla.
I just disabled this editor via Global Configuration on your site >> edit an article to correct format and it's showing fine now. You can apply the same for other articles.
Here is default mockup of an article:
<div class="event-wrap">
<div class="date"><span>22.09</span></div>
<div class="title"><span>Suncorp Stadium, Brisbane, Australia</span></div>
<div class="link-buy"><a href="#" title="Buy tickets"><span>Buy tickets</span></a></div>
</div>