tl;dr: upgraded to 1st then forced to move to middle seat at back after original seat give away No compenstation.

After more than ten years at Platinum or Diamond status and 1.6M base miles, I had my worst Delta experience ever yesterday. I'm still stunned.

As usual these days, first was full but being Diamond had me at the head of the upgrade list. I already had bulkhead seat 4F (A319) so I was not too worried about not getting upgraded.

Ten minutes before departure (IND->MSP) I got the call from the gate agent and was moved up to 2B. So far so good.

But just after getting settled in 1st, the gate agent came on the plane and told me they had made a "computer mistake" and needed my seat for a passenger who was originally checked in at that seat. Things went downhill from here.

The gate agent then informed me that they had now given my original "Choice" seat to somebody else and would I please go to the back of the plane and sit in middle seat 17E. I was stunned. Nothing I asked or requested would get her to give me the original bulkhead coach seat back. They were okay with embarrassing me in front of the other first class passengers by moving me back but would not ask the person in my original set to give it back to me.

So I finally asked her what she could do for me? She offered a 5000 mile voucher if I would go sit down in that middle seat at the back. Wow - 5K bonus miles.

So I squeezed myself in the seat at the back - fuming. But then to add insult to injury, the door closed with no gate agent with my promised 5000 miles.

Only later did I realize they had probably sold the bulkhead coach choice seat to somebody for $50 or so and thus did not want to give it back to me.

Has Delta service really gotten this bad ? This would be a piss poor way to treat a regular tourist passenger - never mind a DM / 1M flyer.

Anyone got thoughts on what I can / should do next ?