I missed an outbound leg of a return flight from Sydney to London 15 years ago. When I got to Heathrow to get my flight back, they told me the ticket was void b

I missed an outbound leg of a return flight from Sydney to London 15 years ago. When I got to Heathrow to get my flight back, they told me the ticket was void because I hadn't taken the outbound leg, then charged me 3k GBP for a 'standard ticket'. I spent about 4 months arguing with BA about it and eventually got most of the ticket refunded. I still think about that.