In Aug. 2015, we were taking a family vacation from JFK airport in nyc to Athens, Greece, traveling on Delta Airlines. Our travel agent at Liberty Travel booked our entire trip and took all our money in advance. We were given 4 confirmed/assigned seats and e-ticketed and confirmed prior to our travel. When we got to the airport, Delta told us they overbooked and we were not traveling and that since it was August, it was very busy and they could not fine a seat on another flight. We were in a state of shock. I called Delta and spoke with Susanna Curtis, executive assistant. I told her we had 4 confirmed assigned seats prior to travel and these tickets were confirmed on Sabre, the reservation system Delta uses. I told her I showed the gate agent the detailed confirmation from Sabre and I was ignored. Ms. Curtis insisted we were traveling standby and because they overbooked, we got bumped. This lady would not listen to reason, showed a complete lack of empathy, and then hung up on me. I have since obtained a computer printout report from Sabre, which indicates our specific assigned seats. Thanks Delta and Susanna Curtis for ruining our family vacation with our 2 children.