threeoh

I agree with OP here, with a ~30m delay, their onward connection should not have been cancelled until the flight departed without them on board, or the flight was closing and the inbound hadn't landed. (Not as a matter of law / CoC, but as a matter of the correct thing to do for the customer). Even if their onward flight had not been delayed, it is totally possible the connection could have been made. Especially given that it does not appear that they needed those seats for other passengers from earlier misconnects, not sure why they rebooked OP instead of protecting them on a later flight.

There is a little bit of too-many-parties-involved here. OP gave their money to SQ, but SQ didn't touch the reservation. UA was responsible for their rebooking as the late delivering carrier, and did, but not in a way OP liked. LO was willing to let them on the flight but not without a ticket. KL operated their flight on time and didn't do anything wrong.

I wonder if it would have been possible to buy a walk-up fare on the LO flight and receive a refund on the involuntarily cancelled AMS-WAW leg. If there was a $50-$100 customer service gesture thrown in might have come out even, depending on the fare breakdown of the original ticket.