my brother's account got deleted...2 months of hard work down the drain

If he was violating the rules in some way, his account probably won't be restored. It sometimes takes mylot a long time to get around to all the spammers, copy and pasters, and other kinds of rule breakers, so they think they're getting away with something. Maybe that's not what happened here, and it's just a mistake.

Send a message directly to MyLot and see if they can clarify the reasons why his account has been cancelled.This would be your best bet.