You can use below code:
$args = array(
'type' => 'product',
'child_of' => 0,
'parent' => '',
'orderby' => 'term_group',
'hide_empty' => false,
'hierarchical' => 1,
'exclude' => '',
'include' => '',
'number' => '',
'taxonomy' => 'product_cat',
'pad_counts' => false
);
$cats = get_categories( $args );