Were you oblivious to this fact? This has been known for well over a year now.
Very few banks are bitcoin friendly. A few credit unions might be, but if you openly admit that it's a bitcoin business, you'll get instant shutdown. Can you disclose a bit more info as to how you alerted them it was for bitcoin? Also, banks might close accounts if they suspect ANYTHING suspicious that they can't confirm. For example, receiving too much cash deposits, and withdrawing cash in close intervals right after you deposit. If they can't figure out what the transactions are for, they'll just simply close it.
Like I said, I only deposited my own cash, a few times at that, and then used the funds to buy Bitcoin with venmo, paypal, and through coin.mx.
I heard of accounts getting shutdown for other traders, but I thought it was mostly due to high volumes of cash deposits from customers. Apparently they shutdown accounts just for being involved with Bitcoin.
I also didn't think they would terminate my relationship for lifetime just because they closed the business account. If I knew that I would have never opened a business account.
A review of your posting history reveals you aren't just trading through exchanges but also sell directly. I'm guessing you made no efforts to be in compliance with AML/KYC laws. No wonder you were banned.