Booking.com failure

Ive made an online booking paid as well and was later called to say they've doubled booked the place. Got a call and was advised they will be looking for a new place and cover all the additional charges, I've then confirmed the new place they got and made the payment when arriving at my destination the owner knew nothing about the booking. No one from booking.com has gotten back to me with regards to my payments after I have sent numerous emails. I am appalled by the level of customer service I've received. Id be sure to never use them again!!! Bad customer experience! Not sticking to their promises.