Product: Credit card or prepaid card

I received a Citi Rewards + Card on XX/XX/XXXX with a credit limit of {$2500.00} including a cash advance limit of {$800.00} with no interest on purchases until XX/XX/XXXX. I have always made my payments on time and pay over the minimum amount due when my finances where enough for me to do so, if not I paid the minimum. Looking back over my statements I found that I made a mistake in XXXX. My min due was {$25.00} due XX/XX/XXXX, I paid {$35.00} on XX/XX/XXXX and {$300.00} on XX/XX/XXXX and {$40.00} on XX/XX/XXXX to try and show I am a good customer. I got charged a {$25.00} fee for being late. After that I paid each month on time and paid slightly more than the minimum payment. I used my card heavily and by my XXXX statement my balance was {$2400.00} leaving my available credit at {$53.00}. Due to the pandemic I had no income for 17 weeks. In XXXX I received 8 weeks worth of unemployment and on XX/XX/XXXX I made an extra payment of {$500.00}. Being a single mom most of my life, I like to know I have money to fall back on " just in case ''. Well on my next statement I checked my available credit and it was only {$42.00}, after I made a {$500.00} payment. I called and found out that my credit limit had been lowered to {$2000.00} and the reason I was told at that time was due to the covid19 and that these are hard times for all of us. So I was willing to accept that excuse, but it didn't set well with me. Then over the weekend I was looking at my credit score because I had paid off a few other cards and saw that since Citi lowered my limit my score had  dropped. So I called them on XX/XX/XXXX and I was told that my limit was dropped because my credit score was low in XXXX and they did a 6 month review. He insisted that it had nothing to do with the fact that I made a large payment ( XXXX! ) He insisted that this is normal for them to do in 6 months time. I got my card in XXXX so 6 months after that would have been XXXX and after arguing with him I demanded to speak to a supervisor, which only ended up making me more irate. He would not budge at all and try to fix anything for me. Not to be rude, but I couldn't understand a lot of what he was saying due to the fact they apparently live in a different culture, but I do believe they use that to their advantage. The only thing he used in Citibank 's defense was that I am paying no interest, which yes I am paying on my cash advances on top of fees too. So I proceeded to tell him I will slander their card to everyone I could which will include reviews and XXXX ( it's the best I could come up with at the time! ha ha ) and hung up on him. So, this morning I called them again and spoke with a woman named Sue whose employee ID is XXXX and I asked her if I hadn't made the {$500.00} payment, would I ended up being over my credit limit by {$500.00} and owe Citibank all kinds of fees as well? Her answer was yes. I have all my original papers when I received my card and the only thing I found pertaining to credit limits on page 3 which states, '' we assign a credit limit to your account. Part of this credit limit may be available for Cash Advances you can take in a given period. We may authorize Transactions that cause your balance to exceed your credit limit. '' My credit score as of XX/XX/XXXX was XXXX according to XXXX. I haven't checked my score to see what it was in XXXX, but I will. I don't want to lose all I have written thus far, and with my luck I'd check it and come back and all of this will be gone. ( I'd probably end up smashing my computer ). Back to XXXX  ; I asked here where it states that Citibank has the right to lower my limit due to my credit score,  and I would look for it in my papers. She said in the terms and agreement, which I briefly looked for then told her to read the terms to me and she proceeded to tell me she didn't have them. I said well, look it up on your computer, nope couldn't do that either. I then asked how she knew it was stated in the terms of agreement and she said she " 'just knew ''. I asked her if she thinks her job insults her intelligence and she didn't answer. I told her I was turning them in to the authorities and hung up. 
I am appalled by this company and their actions. I was truly grateful for the card and it got me through the pandemic and I never saw this coming. Why would they check my credit score especially during the pandemic? If I had known this was gon na happen I would have used my {$500.00} towards one of my other cards and my score would have gone up instead of down. Now all they'll ever get from me is the bare minimum which according to them will take me 11 years to pay off and most likely I'll be dead before then ... .. so they're screwed. Hopefully I can help someone else when I write reviews on them so they don't end up like me. I would love to get more than that, possibly get a class action law suit? I'm a very passive person but I'm beyond tired of being treated like I don't matter and that I'm XXXX. 
Thank you!