This just happened to me tonight. Would love to hear everyone's opinion on what occurred and what I should do....

I was returning back to IAH from a day trip to OKC and was booked and checked in on the 4:19 flight. The inbound flight was delayed due to service/aircraft change in IAH on the way up to OKC. Same configuration aircraft as original.

While the flight was in the air I had the united app open and was tracking to see if the times were changing. The aircraft landed around 5pm. What happened next is what I am bothered with.

A few minutes after 5, my boarding pass in the united app disappeared along with my reservation. I then checked the seat map and my seat now showed empty. (Meanwhile this was a very full flight with 15 standbys on the list) A quick refresh in the app later asks me to check in and I clicked and it references the 6:17 flight, which was also 2+hrs delayed. So I ran to the counter and was trying to get the agents attention that my seat just disappeared and he was about to give it away to a standby person. He proceeded to ignore me, start boarding, cleared the standbys into my seat and 2 others, leaving at the moment a full flight with nothing left.

At this point I was livid thinking of waiting there another 3+hrs when I had a confirmed seat on this flight. After the boarding was mostly finished the agent asked for my record locator and said I was on the later flight and didn't believe that I was on this one. Luckily I had saved the boarding pass in my iphone passbook as evidence along with my email from united. He still insisted I was on the later flight. Finally another agent came by and listened and found me the last available seat that just opened???

When I landed I called the united premier desk, explained the situation and asked who changed my flight. She said it was done at the airport and couldn't give any more info. I asked to speak with customer service as I was upset as to the situation and lack of respect at the gate, especially if they were the ones who rebooked me without admitting it. Unfortunately they were closed and I said I would call back tomorrow.

So what happened? Thoughts...

I don't think it was related to the aircraft change as that happened in Houston and had a full 2 hours before it got to OKC and was the same configuration. And the Rez disappeared with no notice in email, right before boarding.

Was it a global services bumping me? But why me, I am platinum with an almost full fare ticket, and surely there were other down the pecking order.

Did I miss a roll call? I along with 2 other colleagues were at the bar right around the corner but didn't hear any announcements. Plus this all happened prior to boarding. Their tickets weren't affected.

Any other thoughts? What should I do/say?

Thx