[azstar]

It's bad business, but it's legal. Your ticket is a contract. When you bought it you agreed to travel on those flights, on those dates. When you failed to use the original outbound flights you violated the contract. Sometimes the "discounted" roundtrip fare is cheaper than a one way fare. Airlines feel that since you didn't purchase a one way ticket at the one way price, they are entitled to collect the difference, and then some. Stick to airlines like Southwest and Frontier who only sell one way fares. That way, if you fail to use the original flight (your remaining unused reservations will be cancelled if you don't notify them before the original flight leaves) you can still use the return flights without paying anything.