Buy More Points Link Shortcode

add_shortcode( 'mycred_buy_points_link', 'mycred_render_buy_points_link' );
function mycred_render_buy_points_link( $atts ) {

    if ( ! is_user_logged_in() || ! function_exists( 'mycred' ) ) return '';

    $atts = shortcode_atts( array(
        'ctype'   => 'mycred_default',
        'balance' => 1,
        'title'   => 'Buy More Points',
        'url'     => ''
    ), $atts );

    // Prep
    $cui = get_current_user_id();
    $mycred = mycred( $atts['ctype'] );

    // Check if current user is excluded
    if ( $mycred->exclude_user( $cui ) ) return '';

    // If users balance is too low, show the url
    if ( $mycred->get_users_balance( $cui, $atts['ctype'] ) < $atts['balance'] )
        return '<a href="' . $atts['url'] . '">' . $atts['title'] . '</a>';

    return '';
}