Unless they want to lose accounts due to their sloppy service, they will address concerns and the trend now is to accomplish this as soon as possible. However, it would be foolish to write a letter expressing outright irritation and disgust as the bank employees are also human and therefore has feelings. One might also injure the firm's pride to the point that they may not even reimburse the charge and tell you to close your account to them.
If one wants to make known his irritation regarding the situation but avoiding any further mishaps or misunderstanding, it would be wise to construct the letter detailing the situation. After this, a statement of dismay is made known. I think the following would serve its purpose:
"When I opened an account, I chose this bank because of its reputation of delivering high quality services and the perks it offers. I'm beginning to think that I have made a mistake by choosing your firm. What I have experienced is not what I have expected of your highly regarded firm.
There are certain frustrating situations in business relationships. The problem, however, is how to convey the message without hurting the feelings to where the message is directed to all the while showing how much stress his conduct has been causing you. ...