Complaint sub-issue: Can't use card to make purchases

On XX/XX/2020 I had made a payment with a late fee on my Citi bank credit card for the amount of {$330.00}. I am now below my maximum credit limit by {$260.00}. My Citi bank app ( where I pay my bill ) tells me my account balance is {$0.00}. I had made a call a few days later and the automated machine over the phone told me I am over my credit limit. I understood it as my credit limit decreased but I was not notified. I reached out to city at their customer service chat on the app and spoke to XXXX. XXXX told me ; and I quote " I do apologize, however the only information available would be in the letter '' in regards to me asking XXXX how come my credit limit has been decreased without me being notified. I thanked XXXX for his time and made a call to city bank credit help number from the app link. I spoke to a woman after verifying all of my information whom did not tell me her name in regards to whom I was speaking to on the line, so she can not be named in this complaint, but when asked if she could inform me when my letter was mailed and when it should arrive approximately she told me it was mailed on the either the XXXX or the XXXX. My letter mailing date could not be pinpointed on a single day even though city bank 's system mailed it apparently. Then in my confusion, the representative submitted a request for a higher credit limit which she explained would not run my credit score at all. After a few more questions this representative informed me my credit balance was the same amount as always and had never decreased. At this time the representative informed me that my information that she had pulled up showed that I still owed {$47.00} because I only paid the minimum due with an interest payment of {$68.00} and a late fee payment of {$40.00}, which would equal {$220.00}. so I told this representative that it shows I still payed {$100.00} more than what she was telling me, so why was I still not getting an available credit on my credit card? Her response was to have me hold for a moment. She came back on the line and told me that my account that she had pulled up shows that I now owe {$110.00}. So now I have more questions because none of this made sense. Finally this representative informed me a few questions later that my card isn't working because the department that processes the payment ( not the believed to be automated system XXXX is closed currently and should go through on Friday. She stated that I should check again on the XXXX of this month. So now I'm left with more questions than I originally had in the first place, such as : Why was I told twice that my credit limit had been decreased and a letter was in the mail TWICE? 
Why was it not decreased, but I was informed that it was? 
Why was I informed that I owed 2 DIFFERENT payments due before my account was in good standings, even though the numbers she gave me did not account for the massive late fees I paid to put my account in good standings? 
Why is this " department '' closed until the last day of the week/month, but not open during normal business hours the rest of the week? 
I had also asked the representative how I go about filing a complain through the consumer financial protection bureau because I felt I was getting the run around. She asked me what it was about and told me that she had submitted it for me, which was a lie because I'm filling it out now and its more than one question. 

My final question is why is it that every Citi bank representative I have talked to acted like they know nothing about Citi 's system, how to help me, or what is going on with my account, and they leave me with more questions? 

I am starting to feel like Citi does not actually care about its consumers because it seems like a fairly easy issue to fix or find an answer to, and after the representative told me what I was charged {$330.00} for, I am starting to believe that I have been charged {$100.00} for no reason at all. But she couldn't answer that question either. I have not been rude over the phone, I was very calm and willing to listen to what the representatives had to say, but Citi seems to not care if I get help at all.