Hi there Yaman, welcome to our Community.

This sounds like two correction fees have been charges, of which one by OVpay. That transaction can be fixed yourself on their website.

For the NS Flex one I recommend contacting our customer service if it can't be corrected in your Mijn NS account.

thanks @Tomas NS for your reply, I tried to submit a refund on the website https://zelfregelen.ovpay.nl/reisoverzicht

they refund 5.5 Euro and charge 14.5 (without 40% flex ns)

but now still got two charges from ovpay (14.5) and from NS invoice 12 … and the normal cost should be 8.5 (after 40% discount on flex) so in total I paid 26.5 Euro instead of 8.5

and it’s not my mistake, I did check in and out but somehow they system did not recognize it.

It was partly your mistake because your bank card or smart watch was scanned (the OVpay payment) instead of your ov-chipkaart, or in this case… both!

This is a nasty situation, because OVpay seems to have corrected the price to full fare for your actual journey. They should reimburse the full €20 because you have an ov-chipkaart.

But then, NS will not easily reimburse you for traveling with OVpay (and give you back the full 12 euro).

Lesson learned… Keep your bank card or phone or smart watch out of reach from gates or poles at any time if you have an ov-chipkaart.

What should be done is:
Have OVpay waive the 20 euro (no intention to tavel with you, good luck with that!)
Have NS correct the 12 euro to the right amount (€ 8,50) because of a missed check-in/out.

Edited y previous reply, the culprit is OVpay, NS Customer Service (phone, chat, social media) can correct the 12 euro to the right amount.