In my second week in the netherlands I went to the station Center to ask some questions about how the OV Kard worked, because I coulden’t contact Ns phone number. So I wanted to enter the station to see if I could find a NS place with a employer that could help me, I checked in and I coulden’t come in. I waited a few minutes I tried to check in again and it said I was already checked in and the doors didn’t open. I waited more time I checked in and that time I was able to get in. I tried to find someone but I coulden’t find and so I checked out in the same place and I searched to travel history and I see the debited me 20 euros, because there was no check out in the one I didn’t even enter the station. 

Is there a possibility to solve this mistake and not need to pay the 20 euros?

Thank you 

Rafael