Booking.com cancelled my trip and refuses to fix their mistake

I booked accommodation through Booking.com one year before my trip. Booking.com confirmed it and took my money.

Shortly before the trip I got a notification that my trip is cancelled and I got a refund for the accommodation. They also made all kind of promises that they would help me re-book, even cover the difference if any.

Based on Booking.com confirmation I booked flights, paid conference fees, took time off for myself and family, etc.

By the time they cancelled my accommodation there was very limited, and therefore very expensive availability of alternative accommodation in the destination city. Booking.com offered few options, such as e.g. in another town almost 2 hours drive away. When I refused those options, they simply said that the alternative accommodation in the destination city is too expensive (despite their previous promises) and refused to help me further.

Booking.com incompetence and refusal to fix caused me significant inconvenience and expense.