Front End submission with meta key

Since the meta data field is already there you should update it.
also you should time the wp_insert_post… here is the revied code

try it and let me know it you encounter problems:

else {

        $title = $_POST['post_title'];
        $meta_box1 = $_POST['wpcf-mob_no'];
        $meta_box2 = $_POST['wpcf-mob_amount'];
        $meta_box3 = $_POST['wpcf-mob_type'];
        $meta_box4 = $_POST['wpcf-mob_status'];

        $new_post = array(
            'post_title'    => $title,
            'post_status'   => 'publish',           // Choose: publish, preview, future, draft, etc.
            'post_type' => 'loads'  //'post',page' or use a custom post type if you want to
    );
    //save the new post
    $pid    =   wp_insert_post($new_post, 10, 1);

    // Do the wp_insert_post action to insert it
    do_action('wp_insert_post', 'wp_insert_post', 10, 1); 
    update_metadata($pid, 'wpcf-mob_no', $meta_box1, true);
    update_metadata($pid, 'wpcf-mob_amount', $meta_box2, true);
    update_metadata($pid, 'wpcf-mob_type', $meta_box3, true);
    update_metadata($pid, 'wpcf-mob_status', $meta_box4, true);


    print '<pre>';
    var_dump(array($new_post, $pid));
    print '</pre>';
}