Code share: You buy a ticket for a decent airline and then they put you on American Airlines. And the AA employee, with a straight face, calls it an upgrade! Which leads on to...
Free speech: Mostly in favour, obvs. But in the US it extends to lying to customers.
many years ago, I had an argument with british airways about code share. I was booked on a flight from north america to the UK, which BA cancelled and told me I'd have to take another BA flight to a different UK city in about 6 hours then a bus back to the airport I was supposed to go to. This happened when I got to the airport and the departure sign was flashing a message to go see the agent, First they told me it was my own fault because I didn't confirm the flight, which was a lie on multiple levels as I'd actually called a couple of days earlier to make sure my vegetarian meal was in the system (and every time I've ever called an airline to confirm a flight, the reaction was always, why the hell are you wasting our time doing this). Then they generously gave me a $5 food voucher to tide me over the 6 hours in the airport, which would buy a coffee and not much more. I noticed a flight in the board in a couple of hours with a BA number and another number and asked whether I could go on that instead of spending all that time in the airport. They said, it's not a BA flight, its a (whatever it was) flight, and I said "you have a codeshare agreement." Which was met by stony silence and I ended up spending many hours in the airport followed by several hours in a bus at the other end