update post meta doesn't fire

Hello peeps of wordpress.
I’ve encountered an issue with update_post_meta, which will be explained below.
I have an array inside of a post called ‘client_notes’
which is an array that consists of 4 fields.
(meaning there’s a Key above those 4 fields)
Yet, when I try and launch an unset for the key (using POST meta)
it doesn’t delete it out of the database, whenever I click another note a different one deletes (wth?)
So I chose to use “update_post_meta” instead,
creating another array without the deleted notes,
and overwriting the other one with it, yet, that doesn’t work T_T.
my piece of code:

if(isset($_POST['delete_client_note']))
	{ 	$note_to_delete = $_POST['delete_client_note'];

		foreach($messages as $key => $message){
			if(($message==$note_to_delete) || ($message==(++$note_to_delete)))
				continue;
			else
			{
				$new_messages[$delete_array_index]['date'] = $message['date'];
				$new_messages[$delete_array_index]['message'] = $message['message'];
				$new_messages[$delete_array_index]['by'] = $message['by'];
				$new_messages[$delete_array_index]['author'] = $message['author'];
				$delete_array_index = $delete_array_index + 1;
			}
		}

		update_post_meta($post_id, 'client_notes', $new_messages);
	}

any insight?