US Bank review: Bank fees and charges

This concerns the period from about Oct `2019 through April 2020. I have an outstanding balance with a US Bank credit card, which I have been paying off monthly for the past few years (including their obscene interest rate). I had hoped to pay it off completely this year.
I paid the bill every month - but mostly by check in the mail (yes, I know, an archaic method). Two of the reasons I did it that way, are
1) I travel a lot, and
2.) I did not have to go to their really dodgy web site that way.
Anyway, in Febuary of 2020 I got a late payment charge, I complained, and they removed it.
But then, I continued to get late payment charges?
What followed were the things you can read about here in this web site - horrendous customer service - both phone, email and fax; especially email! I experienced several of the things other people have been complaining about - apparently, for years!
I filed a complaint with the BBB in June of this year. That didn't take long. The BBB said the bank made a 'response in good faith' and promptly closed the complaint.
I've read through the US Bank's penchant for Overdraft charges, late-payment fee's, and other things. I've contacted the
'Office of the President' in North Dakota (or wherever that is), etc. etc. etc. Whew, this is one rotten bank!
I've even contacted one or two attorneys.
Finally, about 2 months ago, I told US Bank (through an email) that, hey, from now on, I'm only going to pay you $10 a month - until this gets resolved. What I want them to do is go back to let's say Dec. of 2019 and re-calculate this whole mess - without all the the late payment fees(and of course their exorbitant interest rates piled on top of that).
Presently, it's up to 800 or 900$ in bogus charges.
I think I can show that I paid them on time every month - either by check or using their funky web site.
But the problem might be in the so-called E-checks, which it looks like US Bank has all the data.
I also strongly suspect that in the case of the checks-by-mail, their automated system is (or has become) re-set, so that they can recieve the checks on time, but it doesn't cash them (or show them as being cashed) until after the due date. (A.I. anyone?) Whew boy? How would one prove something like this in court?
AND as if all this wasn't enough, I have been stuck overseas, due to clovid-19 - for months now!