Ann: Trading Halt, page-27

This happened to me at a time when I wasn't in a position to be throwing the rest of my spare cash into trading.
I did exactly what @guy.mathews suggested that you do - wait to see what is happening with the TH and if you need to cover the costs, spend this today looking for a good stock that you can buy and sell easily TODAY. Buy the value of whatever you owe on GPP and then sell it again. It will push your settlement back a day.

Maybe you'll even make a profit But even if you make a small loss on your buy/sell trade today, it might still work out better than the fine + not being able to trade in the meantime.