I had a trip yesterday from Schiphol to Amsterdam Lelylaan. When I checked out at Lelylaan, the boarding gate fee of 20 euros were deducted, so what must have happened is that I missed the check-in at Schiphol, although I passed my OV-chipkaart at the check-in point. It must have missed.
How can I correct this to actually pay for my trip instead of 20e? I tried to correct it on https://www.uitcheckgemist.nl/ but my trip is under the exceptions tab.