Values entered in a meta box aren’t saved

You have to remove if($post_slug != $post->post_type){} from save function or change $post_slug = "book"; to $post_slug = "page";. because it check $post slug is book or not. currently post type is page for contact us page. and you have set as book

add_action("save_post" , "wpl_owt_save_metabox_data" , 10 , 2);

function wpl_owt_save_metabox_data($post_id, $post){

    //verify nonce
    if(!isset($_POST['wp_owt_cpt_nonce']) || !wp_verify_nonce($_POST['wp_owt_cpt_nonce'], basename(_FILE_))){
        return $post_id;
    }

    //save value to db filed
    $pub_tel="";
    if(isset($_POST['txtPhoneNum'])){
        $pub_tel = sanitize_text_field($_POST['txtPhoneNum']);
    }
    else{
        $pub_tel="";
    }

    update_post_meta($post_id, "telNo", $pub_tel);


    $pub_email="";

    if(isset($_POST['txtEmail'])){
        $pub_email = sanitize_text_field($_POST['txtEmail']);
    }
    else{
        $pub_email="";
    }

    update_post_meta($post_id, "email", $pub_email);


    $pub_hours="";

    if(isset($_POST['txtHours'])){
        $pub_hours = sanitize_text_field($_POST['txtHours']);
    }
    update_post_meta($post_id, "hourofOps", $pub_hours);
}