Unfortunately I'm not good at JS, I thought you know it. I think it's possible to convert numbers using php as well. I found this easy code:
function convert($post[answers_raw]) {
$num = range(0, 9);
$persian = array('۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹');
return str_replace( $num, $persian, $post[answers_raw]);
}
You need to change farsi numbers with unicode :) Place it inside that function