Complaint sub-issue: Fee problem

So I have been using my Citibank account for approximately 8 years now. I recently decided to have my account closed on XX/XX/XXXX due to inactivity and previous problems I had with this company. I went to a Citibank Branch on that date and have both my checkings and savings account closed and withdrew all the money I had left inside. I went online on that same date to do a final check to make sure there is no remaining balances and that the account was indeed closed. While checking, I found out that Citibank had charged me a monthly service fee twice without my prior knowledge on XX/XX/XXXX and XX/XX/XXXX. According to Citibank policies, as long as I have a combined balance of {$1500.00} I should be exempt and not be charged a monthly service fee. I have always treated my Citibank account as an emergency banking account in the recent years just in case I would need to use it but never actually did. With this said, I always had a little bit over {$1500.00} as the combined balance without any withdrawals or deposits ever made. So technically I should never have to worry about any fees right? Nope, that's not the case for Citibank because they can hit you with a fee at their disposals. This already happened once previously on around XX/XX/XXXX when they suddenly just charge me with a monthly service fee despite my combined balance of over {$1500.00}. I contacted a Citibank representative right away and addressed the problem. It was a hassle but the agent admit it was their fault and refunded that monthly service fee on my account at XX/XX/XXXX. He acknowledges the error, issued the refund and told me I should be all set going forward and not have to worry about any more fees on my account in regards to this. Obviously being the person I was, I believed their professionalism during that time and took his word for it. But guess what! I got charged that same monthly service fee twice afterwards. Due to it being the same issue, I contacted a representative again who then transferred me to a supervisor due to her lack of authority to handle the issue given my account is now closed which was understandable. So I went ahead and informed XXXX ( She refused to provide me her last name 's initial but I manage to get her badge # which is XXXX ), the supervisor, of the situation. So basically to sum things up, I told her I don't know why Citibank kept charging me monthly service fees despite my account having a constant total balance of over {$1500.00}. She responded by saying, well your account balance was under {$1500.00} after the fees was taken so they had to charge me a monthly service fee. I was so dumbfounded after she said that. Really? If you charge me a fee I wasn't suppose to pay in the first place to bring the balance down causing another fee to be taken, isn't that in error of Citibank? She monotonously said nope, your balance is under {$1500.00} so the fee was charged correctly ... Please someone help this lady, this is so illogical. To put salt on the wound, she said it was my responsibility to constantly monitor my account as they send banking statements all the time ( true to a certain degree, but really? ) and I should be aware of any errors. So instead of taking the representative 's word from your company back on my XX/XX/XXXX encounter, I should be constantly on guard to see when Citibank makes another strike and charge me with another monthly service fee. That shift in responsibility and not owning the occasion is just unbelievable. XXXX doesn't show any care or professionalism at all quoting things like how long the call has been like I was wasting her time despite me being patient with her during the whole conversation ... so all in all, because my account is now closed, she don't give half a dam about me or the money they " stole '' from me via their so-called monthly service fees. Before this call was made on XX/XX/XXXX I was still able to access my online account to see the last of my statement but after speaking with XXXX, she apparently closed everything out and denied me access so I wasn't able to provide any additional proofs such as statement balances etc but they should still be on their system ... Giving this is such a huge banking company, I am thoroughly disgusted at how they handle the situation. I am wondering how many more victims there are out there ...