Subcategory issues

Hello everyone! I was adapting a theme to my needs when I found a problem in the PORTFOLIO page. I do not understand that much of PHP, so I’ll try to be as clear as possible with my questions! =)

This page has a portfolio with some categories: TODOS (that shows all the images), DRAWINGS and PAINTINGS (that shows the images on these categories). I’ve added a subcategory called ‘2011’ as DRAWINGS’ parent.

What I am not able to do is to show this subcategory on the page. I want ‘2011’ to appear right below the link DRAWING when clicking.

IMPORTANT NOTE: When I put this code

$terms = get_terms('portfolio_category', 'portfolio_subcategory' $args );

instead of this one

$terms = get_terms('portfolio_category', $args );

The result in the menu is: TODOS 2011 DRAWINGS PAINTINGS

Here’s the code:

[Code moderated as per the Forum Rules. Please use the pastebin]

Thank you guys!