Can Bank of America really do this?

I am currently fighting with BofA. I closed my checking account in May and in July there was a charge that went through on a card, that I did not authorize. I was charged an NSF fee and then five days later charged another NSF fee. The day after I got the notice in the mail I went to the branch and they had already tacked two charges on my account. They said that they charge another fee every five days but they don't send out the notice until the 5th day. How is that fair? If my account had been open I would have noticed the charge earlier but because it was closed I was not watching the account anymore. I asked them how they open up a closed account to put a charge on there and they said because it was a card they assume that it was authorized. Can they open a closed account and file all of these charges?