Complaint sub-issue: Difficulty submitting a dispute or getting information about a dispute over the phone

I reached out to XXXX XXXX with Citi Bank via email onXX/XX/2019 in regards to asking for a good will forgiveness on a {$180.00} balance I forgot to make a payment on ( I paid off immediately after learning about the late payment ). Then on XX/XX/XXXX XXXX from the executive office in SD contact me right away and I really appreciated the quick response. When XXXX contacted me she stated she couldn't help me with my account. My credit means so much to me I didnt want to give up, and asked her if you were in my shoes, would you give up or is there someone else that you would try to talk to? And she stated to me she would have her manager XXXX call me and maybe I can work something out with her. Well, XXXX and I played phone tag for 2 days and never had the chance to speak, as she stopped calling me back. But I did get a credit notification that my Late payment was removed from my account and I was back to 100 % payments on time. Then soon after I received a letter in the mail from XXXX stating she had confirmed that the late payment was removed, I called and left XXXX a voicemail thanking her and I thought my dilemma was over. About 1 or maybe 2 weeks later, I received a notification that the late payment was back on my credit and I went to look for the letter sent to me from XXXX to send it in to the credit agencies and couldnt find it. I called XXXX and left a voicemail requesting a copy of the letter sent to me and got no reply. A few days later I reached out to XXXX and left a voicemail. She called me back a day or two later which was XX/XX/2019 in the late afternoon and said she would send the letter on Monday ( XX/XX/XXXX ) when she was back in the office. I thanked her and waited patiently for a letter that was never sent to me. After checking the mail everyday that week, I finally reached out to her on Thursday or Friday ( XXXX or XXXX ) to confirm the letter was in the mail, since I had a feeling I was forgotten about. She returned my call XXXX and we had a rather puzzling conversation in which she told me she didnt know how my late payment was removed because she didnt do anything to remove it, In which I figured it was XXXX that helped since the letter was from XXXX, and all I wanted was a copy of the letter that was sent to me in which XXXX said she would email me ( confirmed my email address ) and send me a copy via mail. I refreshed my email all day looking for the email that again was never sent. I called back multiple times in the afternoon after letting hours pass thinking she just needed some time to get the email out to me and my calls werent answered or returned that day. I honestly lost sleep that night thinking about it and 1st thing the next morning ( XXXX ) I called and left another voicemail in which she returned my call pretty quick and she had informed me she was waiting on approval to send the letter back out to me. Ive been in customer service all my working life and I have my on own business and communication is a huge key factor in building relationships and I was bothered to not only hear she needed approval to send a letter that was already sent to me, But I waited nearly 10 days for a letter in the mail that was never sent to be told, she needed approval. On XXXX i emailed XXXX XXXX again about the letter and sharing the experience i was having with the corproate office. A coulple hours later, XXXX contacted me ( 1st time speaking with her since i started reaching out ). She refused to send me the letter even stating it was " accurate at the time '' but the not anymore. I dont understand how she can withhold a letter that was sent me to me before. I asked her to escalate the situation to her boss and when asking for her supervisors name, she refused to give me her first name and only said it was Ms. XXXX. This experience has literally caused me to lose sleep as its been very frustrating at the lack of communication and strong disregard for customers from XXXX at the Citi Bank executive office in South Dakota