Hi Eirini, welcome to the Community.

It looks like you used an OV-bike for a few days. After 72 hours of use we charge € 5 per day extra. Your rental period started on October 29 and we charged € 5 extra per day starting November 1st.

You can find the rates for the OV-bike here.

Renting an OV-bike costs €3,95 per 24 hours. After 72 hours there is an extra charge of €5 per 24 hours.

Your rental period was 7 periods of 24 hours, of which 4 periods after 72 hours.

See also https://www.ns.nl/en/customer-service/ov-fiets/how-the-ov-fiets-works.html

Welcome to the NS Community!

If you rent an OV-fiets for more than 3 days (72 hours), a surcharge of € 5,00 per 24 hours will be applied.

It looks like you rented one from 29-10-2021 @ 6.23 pm until 04-11-2021 @ 7.20 pm, so that counts as 7 days.

7 × € 3,95 = € 27,65
Surcharge for 4 days (longer than 72 hours) € 20,00

Returning the bike one hour ealier would have saved you € 8,95

It also looks like you took an OV-fiets on the 29th, and returned it within 15 minutes (maybe because it was defective?)

If there is any error, contact NS Customer Service. Where it shows ‘Unknown’ it should show ‘deur tot deur’ (door-to-door) services.

Also, fun to see that your NS app/phone translates the dates to Greek.

That's probably taken from the phone's OS. I have an English language app that shows dates in Dutch.