Denali State Bank Improper account charges Fairbanks, Alaska

My nonprofit, of which I am Secretary/Treasurer, had a free checking and savings account with this bank. Without proper notification this bank changed the checking from a free checking account to a monthly fee account. This sudden change then also resulted in a large insufficient funds fee since I had deposited the exact amount in checking and when they charged the account a monthly fee the account was short by that amount.I contacted a manager and explained the situation and was told tough luck. I asked to speak to another manager and they said the same. I moved the account the same day to another local bank that was highly rated for customer service.When I closed this account the teller told me that others had the same problem with this surprise fee(s). Absolutely terrible customer service at this bank.