I Cannot Cancel My Free Cancellation Bookings on Booking.com Anymore

I am a Booking.com Genius Level 3 customer and made my last 11 reservations with the "free cancellation" option, but I’m unable to cancel them. For the past month, the system hasn’t allowed me to manage any of my bookings, and as a result, I’m at risk of being charged €18,000. This is quite stressful, especially since I booked with confidence in the platform’s cancellation policy. I can’t reach customer service or even find an email address to contact; the system keeps directing me to the hotels’ customer service, but they claim they can’t do anything. I’ve spent hours trying to resolve this through the app and website, but nothing works.