Last week, I forgot to check out at Schipol airport. I tried so many ways by asking customer service at NS central station Amsterdam, but they had nothing to do with my case and said that i can only request it by myself on Mijn NS. However, it showed only “You cannot claim a forgotten check in or check out for a trip with an NS Flex product.”
I am quite upset for this inconvenience, hope someone could help with the same issue happen?