I made an oral contract with someone to participate with them in an event in another city. In doing so, I spent $450 for my ticket. When that person related my participation to the organizer, the organizer forgot and filled the spot with another participant, leaving me short $450 and no spot in the event. Before spending the money, I asked at least 3 separate times if it was truly a go. The answer was yes each time. I will be charged $360 to cancel the flight. This person thinks it is not their responsibility, since I bought the ticket and somebody else filled the vacancy. Who is responsible for the loss? Should I sue? Are there other options?