Hello! I was travelling from Duivendrecht station to the center of Amsterdam yesterday and in a hurry mistakenly checked in through the train (NS) gates at Duivendrecht station. When I realised this, I went back (albeit after a couple of hours) and checked out at Duivendrecht through NS again.
I was charged €20 on my card. Is there a way I can get this amount refunded? How can I go about the process?