I was on the SAN-LHR yesterday which seemed to be massively oversold. They were pro-actively offering $800 to people who voluntarily decided to be rebooked on the next day's flight.

I was travelling with 9 colleagues all of whom were on separate tickets in various classes. 3 were upgraded from WT+ to Club and 2 were downgraded from WT+ to WT. 1 was told she was on "standby" and couldn't be guaranteed a seat, but ultimately ended up travelling in WT+.

I was sitting in my WT seat and someone else boarded with the exact same seat number. I refreshed my BA app to discover I now had a WT+ seat.

After fighting against a wave of people boarding the plane and reaching the WT+ cabin, I found someone sitting in "my" WT+ seat. I queried with the cabin crew who ended up moving the lady to a seat in WT and I ended up travelling in WT+.

As you can imagine my colleagues were bemused.