Hi, I am disputing with American over a flight. They claim that I was not at the gate in Seattle Tacoma Airport by the time my flight had closed the gate for departure. Before my flight, I distinctly remember handing the ticket agent my ticket, the she scanned it, then she walked over to the gate to announce a final boarding call. I was then not allowed on board. Since I abode by American's "15 minutes before departure policy," they are at fault in this situation. I am requesting the footage of this so that I can show that to American and receive a refund for my flight. Please let me know next steps.