Booking.com unreliable left me stranded cancelled two properties on me

Had two properties Cancel on me for my recent trip to London. The one they were unable to get hold of me as I was traveling I ended up stranded on the street in London with bags and all. Have been using booking.com for a while but never again after this I understand they were unable to get hold of me but why was everything confirmed I have confirmation latter instructions of how to enter the property directions from host. These people are so in organised.