I can't edit my post so i just add new one.
The solution from https://github.com/woothemes/WooCommerce-Quantity-Increment/issues/2
The solution descover jameskoster and the code write bryceadams.
You need to add this code to your 'custom function' area in function.php
add_action( 'wp_enqueue_scripts', 'wcs_dequeue_quantity' );
function wcs_dequeue_quantity() {
wp_dequeue_style( 'wcqi-css' );
}
It works for me. Hope this will help you too :)