Well yeah, its an intended behavior, the My Trades page only shows your private trade offers which you can accept and complete immediately. You can make partial trades show up too, but then you may need to edit other parts of the code, since a partial trade is not meant to be 'accepted', it needs to be forward back to the user asking for trade to complete the trade offer.
Well I dont think theres anything you can do about autoban for now. But you can manually change yourself back to admin user after you are banned. Go to CPanel, and click PHPMyAdmin, select the mysidia database. You can edit your admin user for table adopts_users and table adopts_users_status, and manually unban yourself.
Okay your account should be working again. I think what you did with promocode triggered autoban, since the system bans users who attempt to use promocodes that belong to other users.