Kept my account open without my knowledge to gain service fees

I had an account with RMB for over 4 years, with fair (not great) services. I requested my account to be closed in mid-June, received a notification it will take two working days. I made sure both my credit and cheque account was balanced so that no additional admin was needed. Two months later I get a notification that they can't close my account due to outstanding funds. RMB kept my account open, charged me two months of service fees and also started pulling interest on that - for all purposes this account wasn't supposed to be open and any payments should have bounced. How can you charge service fees when there was no service even used? Really terrible private bank.