Change user role based on total number of items ordered.

Trying to get this function to work. The first one works fine, it gets the total number of items ordered by a user (all time) and the second one is supposed to change user role based on the total items.

function get_user_total_purchased_items( $user_id = 0 ){
    global $wpdb;

    $customer_id = $user_id === 0 ? get_current_user_id() : (int) $user_id;

    return (int) $wpdb->get_var( "
        SELECT SUM(woim.meta_value)
        FROM {$wpdb->prefix}woocommerce_order_items AS woi
        INNER JOIN {$wpdb->prefix}woocommerce_order_itemmeta AS woim ON woi.order_item_id = woim.order_item_id
        INNER JOIN {$wpdb->prefix}posts as p ON woi.order_id = p.ID
        INNER JOIN {$wpdb->prefix}postmeta as pm ON woi.order_id = pm.post_id
        WHERE woi.order_item_type = 'line_item'
        AND p.post_type LIKE 'shop_order'
        AND p.post_status IN ('wc-completed')
        AND pm.meta_key LIKE '_customer_user'
        AND pm.meta_value LIKE '$customer_id'
        AND woim.meta_key LIKE '_qty'
    " );
}

add_action( 'woocommerce_order_status_completed', 'change_role_on_purchase', 20, 2 );
function change_role_on_purchase( $order_id, $order ) {

    $user_id   = $order->get_customer_id();
    $user      = new WP_User( $customer_id );
    $purchases = get_user_total_purchased_items( $customer_id );

    if( $purchases >= 50 &&  $purchases < 100 && ! in_array( 'bronze_user', $user->roles ) ) {
        // Remove role
        $user->remove_role( 'subscriber' );

        // Add role
        $user->add_role( 'bronze_user' );
    }
    elseif( $purchases >= 100 &&  $purchases < 200 && ! in_array( 'silver_user', $user->roles ) ) {
        // Remove role
        $user->remove_role( 'bronze_user' );

        // Add role
        $user->add_role( 'silver_user' );
    }
    elseif( $purchases >= 200 && ! in_array( 'gold_user', $user->roles ) ) {
        // Remove role
        $user->remove_role( 'silver_user' );

        // Add role
        $user->add_role( 'gold_user' );
    }

}

Anyone have any ideas why its not working?