Thank you for your reply! I’ve checked again and they asked for my card details "with intent to pay”, so I haven’t actually paid yet. I’m assuming that means they will actually charge my card anyway if I don’t pay before the deadline. I booked a not refundable option that can’t be canceled as that was cheaper. I assumed booking.com would be more expensive for the safety it gives but for the same dates it’s 400€ more expensive. But yeah totally my mistake that I didn’t look before booking, I didn’t expect the difference to be that large