I booked a trip with KLM, but since I wasn't 100% sure about the dates, I didn't book a 'Basic' fare. Instead, I paid an extra €30 for a 'Light' fare, which allows for subsequent date changes.

Now I need to change the dates, but Customer Service says that the 'Back Office' has to handle it for me. However, the Back Office keeps emailing me from a 'no-reply' Email-address, which means I cannot send them the proof / screen-shots they, for some reason ?, require.

The trip is in 10 days; if nothing changes, I will lose the entire €250—including the extra €30 I paid specifically to avoid ending up in this situation.