I have left my bag in the bag locker at Amsterdam Central for 24h (paying 10 euros).
When I came to pick up the bag - 26h later (that is, just 2 hours over the time) - the machine charged me 15 euros on top of the 10 euros I had already payed.
I complained with the people working there but they said they could do nothing about it and that I should complain for the reimbursement here. So PLEASE PAY ME BACK MY MONEY!!!