Can’t Change My Hotel Departure Date With Booking.com

My Booking.com reservation under confirmation number 5272825896 is for Royal Apollonia in Limassol, in the name of Fabian B***. I would like my hotel departure date to be changed from 22 June 2026 to 21 June 2026. Since 24 April I have attempted to make this change online through your system approximately six times. Each time I go through all the steps, including reaching the refund and charge card page, but after completing the process the original departure date still appears and the change is not applied. I contacted the hotel directly about this, and they informed me that only Booking.com can make this change on the reservation. Therefore, I request that you update my booking so that the departure date is 21 June 2026 instead of 22 June 2026 and confirm this change to me in writing as soon as possible.