After two days with this problem have resolved the problem, I fix it adding tax_query parameter with my taxonomy name and slug of the category requested:
$args = array(
'post_type' => array (
'servicios' => 'servicios',
),
'tax_query' => array(
array(
'taxonomy' => 'category',
'field' => 'slug',
'terms' => 'dgit'
)
)
);