I was a long term client of booking.com. But recently we had booked two different nights at the same hotel after we decided to extend our stay. I requested to combine the booking and both Booking and the hotel Hotel Klaus K in Helsinki told me I could. But they simply added a day to the fist booking and left that same date on the other booking, so double charging me and booking not only refused to correct this but refused to speak to me and under their messages continued to send out a generic response refusing to correct their mistake. In the past we had booked 15 to 20 bookings a year with them but loyalty to them is a one way street. They have the WORST CUSTOMER SERVICE of any company I have worked with in 50 years. Eric Davidson