I sold 3 upper classes at 1:00 o'clock yesterday. I just came online and saw that the 300k just disappeared. Play by the way on PS4
To contact support, I would say.
Look if the upper classes are still there!
Sometimes it is so that the server was offline and everything was not saved in the session.
I have often happened. I finished a job then increased my rank and the next day everything was the same as before
Rank is reset and the upper classes are gone.