Avoid Booking.com- Terrible

At least twice my bookings were cancelled without my permission. In both instances I received the email that they cannot accommodate me on the stated dates after the same bookings were confirmed by them. Worst the last one I booked in advance more than two month, a day before the day of accommodation I received the email from them that they can't accommodate me on the said date. On other occasion they gave me an accommodating for 4 people while they confirmed that it can accommodate 5 people.