Product: Checking or savings account

I have a checking account with Bank of the West. I had opted-in for overdraft protection. On XX/XX/XXXX made number online purchases. Prior to each transaction my checking account showed a positive balance, using Bank of the West 's phone application. Each transaction lowers the Available Funds immediately. This is how I knew I had a positive balance. On XX/XX/XXXX, I initiated an {$80.00} balance transfer from another account to this checking account. I then made one online transaction for {$81.00} ( apparently broken into two separate transactions of {$77.00} and {$3.00} by the merchant - between product and shipping charges, not sure what they do this, as I authorized one charge of {$81.00} ). This was the only purchase transaction of the day. All others had posted according to the Available Balance. Unfortunately, the {$80.00} balance  transfer did not post on XX/XX/XXXX and resulted in an overdrawn account. The next day, on XX/XX/XXXX, I received five {$35.00} overdraft charges. Once I saw the charges, I called Bank of the West to ask how one charge could result in five overdraft charges. I was told that some charges from  XX/XX/XXXX had not posted before the account went negative and that each charge then generated a {$35.00} fee ( i.e., {$170.00} for one charge ). The next day on XX/XX/XXXX, XXXX more overdraft charges of {$35.00} showed up in my account. I called again to ask what was going on and was told additional charges from XX/XX/XXXX had not posted until XX/XX/XXXX while the account was negative. The new fees were attributed to charges also made on XX/XX/XXXX. Now I have {$350.00} in overdraft charges due to one online purchase made on XX/XX/XXXX. The following day on XX/XX/XXXX, five more charges showed up in my account. Now there were {$520.00} in overdraft fees from one online purchase. I called Bank of the West consumer service three times and was told there was nothing they could do. I was then referred to the branch manager of the branch where the account was opened. I spoke with XXXX XXXX in XXXX, WI. He told me that I overdraw my account and that all charges were valid and he would not reverse any. This is totally wrong. There is one charge that should have resulted in an overdraft fee and that was the one the caused the account to go negative made on XX/XX/XXXX ( see attached ), before the balance transfer was posted. There were {$35.00} overdraft fees charged online purchases of {$.00}, {$1.00}, {$1.00}, and other small amount. They appear to be reaching back to prior days to assess fees. At least thirteen of these charges are attributable to charges made on XX/XX/XXXX ( see attached example ). This by itself can not be right as I thought there was a limit of five overdrafts fees in one day. The attached documentation from the merchant showing exactly when each charge was authorized ( amount, date and time ). By opting in, I agreed to pay overdraft charges when I overdrew my account. This only happened with one charge not fifteen. Everyday that I called and complained that  added additional fees to apparently penalize me. This is unethical and can not be legal. There must be banking standards/rules that protect consumers against this type of banking scam. It's predatory banking in my view. Any assistance you can be provide would be greatly appreciated. Thank you.