Booking.com Reservation Not Found by Hotel After Payment in Milan

Two days ago, I made a hotel reservation through Booking.com at B&B Hotel Milano Central Station in Milan, Italy (Reservation No: 840108805504301439). The amount of €329 was charged to my credit card. However, when I directly contacted the hotel, they told me that no such reservation appeared in their system and even suggested that the booking might be fake.

I reported this issue to Booking.com customer service, but I did not receive a clear response, and during the call, the line was even disconnected. My reservation was neither canceled nor changed, and no solution was offered.

This is the first time I have experienced such a problem, and I want my issue resolved. I request either a full refund of the amount paid or a proper reservation change.