Booking.com Missing Refund Issue

I had a reservation on Booking.com with confirmation number 4190968*** for December 31, 2023, to January 1, 2024. Two days before my planned arrival, I contacted them, only to be informed that the facility had closed. During my conversation with customer service, they assured me that any price difference for a new reservation would be covered, up to €309.28 compared to my original booking. Due to limited options on New Year's Eve, I made a new reservation at another hotel (confirmation no: 4007205129) and submitted the invoice to Booking.com after my stay.

They refunded me €246 but deducted €48 for breakfast, claiming it was an extra cost. The hotel, however, was advertised on Booking.com as including breakfast in the room rate. We didn't incur any additional expenses. Despite assuring me that the price difference for my new reservation, up to €309, would be covered without specifying any conditions, they failed to inform me otherwise. I request a refund of this charge, as I was left uninformed and disadvantaged until the last day.