Solved

£3m Penalty For Leaving League

I left the league I was in 1 race before the end of the season.
I was in last place, and it wouldn't have mattered where I'd finished in the last race, it would not have affected the other people's final positions, as there were at least 100 points between them.
There were also only 6 teams in the league, meaning that there was zero chance of anyone being promoted or demoted either.

I was fined £3,443,000.

Don't think this is particularly fair.

Hello,
We have refunded the penalty money.  This was a bug.

Thanks Justin.