Back in 89, I was headed on BA to London. Sat at JFK for 7 hours. . . ON THE PLANE!
We got all the way to the runway, shut down. Go off to the side. Then back somewhere else. Then back to the terminal. THEN the pilot finally "puts his foot down" and feeds us - hours late. 8 seconds later, they get us a plane. "We'll let you finish your food before we move to the other plane."
NO! I WANNA GO NOW!
Oh, and they didn't tell us the plane wasn't restocked, so take your blanket and headphones. Nope. Get over there. "Oh, sorry. We don't have any." Complete disaster.
I had been on that stupid plane from 9pm to 4am. Didn't arrive in London until EVENING instead of morning. Wasted a day. "Sorry old chap."
Oh, and my then-GF/now-Wife who was meeting me left me a note. Do you think there would be 2 Dennis in MA's on that flight??? And the loser that WASN'T me (as opposed to the loser that was me) read the message AND KEPT IT!

Never a thought that there might be two of us on the plane. Glad the gate girl remembered the message.
Security at Heathrow and then at DaVinci was interesting. I flew out the 1st anniversary of Lockerbie. Coming from a very-pre-9/11 world here. Guard with submachineguns in DaVinci. VERY good (and friendly) TSA-like security at Heathrow.
So I can feel your pain - sometimes they just f it all up and then can't seem to fix it.