| Their customer service was absolutely horrible in Denver. My Norwegian flight from Paris to Denver was delayed by an hour - I even received a notification. When we arrived in Denver, it took about 20 minutes to get off the plane, followed by another 20 minutes to retrieve bags and go through customs before checking in to my connecting flight. I get to the Frontier Airlines kiosk and the agent told me I could not board the aircraft 30 minutes before departure - yet in their terms and conditions, it says that passengers are allowed to board up to 30 minutes before departure - either this agent was purposely making this experience hell for me, or was a complete idiot and had no idea how to do his job. I tried explaining to them that my flight was delayed and I had come up to the kiosk as fast as I could after having to wait through customs and baggage claim. The agent alongside him said I needed to calm down and that I was flabbergasted - no regard nor understanding to the frustration after flying 11 hours, and then being told I would not make my connecting flight and that "it's not their fault I missed my flight". The agent also said that they do not receive any notifications at the kiosk about delayed connecting flights, which I find absolutely absurd. They told me I needed to go speak with a manager but there was no one to be found at the moment. I spoke with Spirit Airlines next door, they said I would have to pay for a new flight if I were to fly with them - but that I could attempt asking the manager from Frontier Airlines if they could assist with that. The manager was now at the kiosk at Frontier, and her presence, attitude, and tone of voice was the worst I have ever experienced at an airport. She was extremely rude, and would not even listen to anything I tried to explain and kept dismissing every sentence without thought. She was robotic in tone of voice and did not care at all about what happened with my flight, and blamed me for missing the flight and that there was nothing they could do. I left crying out of frustration and rudeness that I experienced from that so-called "manager" - it's a mystery as to how someone with such a horrible attitude and personality would have that role. I had to buy a new ticket from another airline, as well as transportation and hotel for the night since they had no other flights to offer me. This airline doesn't care about it's customers, nor do they offer any type of class in their customer service. What a disgrace.