Problem when making payments: Credit card

I am submitting a complaint about Bank of Americas AutoPay system, misleading mobile UI, and confusing notifications, which ruined my credit score after five straight years of never missing a single payment. I have been a loyal customer for over five years with a perfect payment track record using AutoPay. I had set a maximum cap on AutoPay as a standard safety limit. When my balance went over that cap, instead of paying up to the cap or at least covering the minimum payment due, Bank of Americas system silently canceled my ENTIRE payment without warning. To make matters worse, their app and email alerts did not make it obvious that anything was wrong. The subject line for a canceled payment looks very similar to the standard monthly confirmation email. On my phone screen, the subject line was actually so long that the words " has not been scheduled '' got cut off completely, so it looked like a normal AutoPay confirmation unless you opened it and read every line. The first paragraph of the email body did not even state any call to action or signify that anything was wrong ; it was a loquacious and mundane description of my AutoPay setup. When my bills did fall past the deadline, the notification email contained the subject line " Important Account Servicing Information ''.... that came on the heels of a different " important account servicing '' email just telling me I had to update some information in the next few months! On top of that, when I logged into the mobile app, there was no red warning banner alerting me to the delinquency of my account. The top right corner showed I had messages in my " Inbox '', but that could have been for anything, including marketing emails ( of which I receive many emails for as well ). The app technically has push notifications, but you need to enable them one by one for each notification type behind a menu that only discusses emails until you navigate two submenus deep. Due to all these non-obvious design choices, I had no idea my account was past due for two cycles. Of course, the second I noticed what had actually happened, I paid the balance in full and fixed my settings. When I called customer support to explain that my late payments were caused by confusing UI, they spent over an hour insisting I didn't even have AutoPay turned on, and that it was enabled through Bill Pay from my origin bank. I gave them tons of evidence to the contrary but they kept telling me the problem was with my bank and not them. After a supervisor finally admitted I did have AutoPay enabled, they changed their tune and lectured me on how they technically sent statements and emails and they did everything they could. I understand that I had the means to discover that my statement wasn't being paid off, but I also believe that BofA had the means of receiving their payment from me and chose to not take it, and their customer service department was more interested in denying my experience than attempting to understand it, let alone address it.