Booking.com Overcharged Me for Midilli Island Reservation

I booked a one-night stay for two people on the island of Lesbos through Booking.com on May 9, 2024. My reservation number is 4539072210. The price shown at checkout was €44.55, but when the payment went through, €73.01 was unexpectedly taken out. We reached out to both the hotel and Booking.com regarding the issue, and the hotel stated that the charge was for cleaning fees, even though we were not notified about this additional cost when we made the payment. We attempted to cancel the reservation, and now it appears that only €28.46 will be reimbursed. We're having trouble finding someone to help us with our concerns from either party, and we're insisting on getting a refund for the service we didn't get.