I Booked 2 hotel rooms for 2 different nights, one through the Trivago app and the other through the Booking.com app. I needed to change my reservations for both nights. The Trivago app offers no options for changing an existing reservation. Booking.com has a link on their app. I had to call Trivago directly to get assistance on changing my reservation. I was told that someone would return my call in 15 to 30 minutes. Nobody ever called me back. I was able to change my reservation through Booking.com with a simple click on the link they provided on their app. I just added my new dates and they changed my reservation. The rate was actually lower on my new dates, and Booking.com immediately refunded the difference to my account! Trivago never called me back to change my reservation. I called them back again and was told again that they would call me back within 30 minutes. Trivago never called me back. I will never use Trivago to book a hotel reservation ever again and I have uninstalled and deleted the Trivago app off my phone. Terrible customer service!