Most commodity markets do not have any kind of "confirmation" period, once an order is placed, it is placed, and you can try to cancel it, but the exchange and your broker will attempt this on a "best effort" basis. I do think that the market is not large enough to really support both bids and offers so only offers (and buyers accepting sellers' offers) will need to remain.
That's not the full picture. At the very least most such exchanges / software tools would have an option (often the only one or the default) to enter price per unit. There is no reason for Zen to use the total price as the basis and it doesn't even show price per unit anywhere in the process. Not to mention that you can't even see your own hashlet in the market, doesn't make sense at all. Poor UI design + target customer base of "people new to mining" = disaster.
Half of what you said here is completely irrelevant to the accusation.
He picked the wrong hashlet and confirmed it. Your hashlet not being visible on the market has nothing to do with it!
I accidentally clicked on the 70 MH hashlet on accident and typed in the price of what I would sell the 1 MH Zen hashlet for (thinking I was selling my 3rd and last 1 MH zen hashlet).
The real issue here is OP saying he was "fucked over" which in fact is a lie. He fucked himself and blames GAW, which is pathetic.