Product: Credit card or prepaid card

I have been paying a {$150.00} minimum payment for several months. For XXXX 's statement, the min payment went up {$3.00} to {$160.00} for that statement period. I was told by a bank rep that this was due to XXXX having 31 days in the billing cycle as opposed to the previous few months only having 30. 
So for XXXX 's statement that was due on XX/XX/2018, I sent in the {$150.00} that I have been paying for a few months. I did not realize the increase of the {$3.00} because my wife receives the e-statements via e-mail from this bank and I recently took control of paying the bills in the house and she did not tell me of this {$3.00} increase in the minimum payment for XXXX. 
I made the {$150.00} payment for XXXX that was received by the bank on XX/XX/18 with a due date of XX/XX/2018. 
I was assessed a {$27.00} late fee for not paying the full minimum payment due and not because the payment was late. I telephone the bank in XXXX when I noticed the late fee and explained the situation. I was informed the late fee would be removed from my account. However, their was miscommunication between myself and the rep because I believed that {$27.00} late fee would be removed from my total minimum payment for the following month, however I was told later on that this is not the case and that late fee would only be removed from my total overall balance with the bank. So with that in mind, I paid the original minimum payment of {$160.00} for XXXX 's statement with the knowledge that I wouldn't be charged {$27.00} late fee. 
This was not the case as I was charged another late fee for XXXX statement because I did not pay the full minimum payment of {$180.00} ( {$160.00} plus the {$27.00} late fee ) for the prior month thinking that late fee was waived. So with the current XXXX statement ( due XX/XX/2018 ) I was assessed another late fee of {$38.00} bring XXXX minimum payment to {$220.00}. 

I noticed this and contacted customer service on XX/XX/2018 and described this whole situation. I was told that the two late fees of {$27.00} and {$38.00} would be waived from my TOTAL ACCOUNT BALANCE but not from my current min payment due on XX/XX/XXXX of this year. I asked to speak to a supervisor. When I did I informed her of the situation and she confirmed the two late fees were waived but the {$220.00} minimum payment due could not be lowered. I asked for an explanation why the minimum payment could not be reduced because I agreed to these terms and conditions when I opened the credit card account initially. 
I then attempted to make the point that a {$3.00} mistake on my part initially, 2 months prior, has now ballooned into an increase of {$60.00} that I would have to make on the current statement and how unethical and wrong this situation appears to be. She informed me that their was nothing that could be done with regards to the amount minimum pay due because of the original terms and conditions and due to the fact that the minimum due has already been " cycled ''. 
I informed the supervisor that I believed this was unfair and I would seek remedy to this issue. 
That is the final correspondence with the bank and where we stand at the present time.