You don't give a whole lot of information to go on, but if you have NS Flex, travel costs are only deducted from your bank account once: at the end of each month, after you’ve received the invoice. They should not be withdrawn from your account the day after you've travelled. That would only happen if you use your bank card to travel. But if you have NS Flex, you would never use your bank card to check in or out, only the OV-chipcard that has NS Flex on it. And if you did use your bank card, you should not get an invoice for travel costs.

This community is meant as a place where travellers can be helped by other travellers. We are not NS employees and do not have access to customer data, so we can't look at your travel transactions to see what exactly might have gone wrong. To talk to someone who can, which might clarify things further, you should contact customer service directly. This can be done by phone; they are available 24/7 at 030-751 51 55. You may also contact them by chat (click the link Chat with NS on this page) or by sending a message on X (formerly Twitter) or Facebook.