Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

XX/XX/XXXX I received a statement for {$3600.00}. I paid this in full, on time. After that I stopped using this card and received no further statements. 
XX/XX/XXXX I suddenly receive a debt collection letter from XXXX XXXX XXXX on behalf of Elan Financial Services for {$7300.00}. I had never heard of Elan Financial Services before, as far as I knew my credit card was with XXXX XXXX XXXX. Every single statement I had received from when I opened my account until my final statement on XX/XX/XXXX never mentioned Elan Financial Services anywhere.

Once I was made aware that my card was actually with Elan Financial Services, XXXX XXXX XXXX sent me all statements, at which point I was able to see that fraud had been committed with my card. I had never received any statements past XX/XX/XXXX, despite there having been activity present ( not by me ). 
Had Elan continued to send me my statements, I could have alerted them to the fact that there is fraud. Elan simply continued adding late fees and interest charges to my account, never contacting me, never sending me a statement or any other documents to let me know what was happening. Apparently my card was being used in XXXX and XX/XX/XXXX still, and it wasn't me. They also neglected to alert me when my credit limit was exceeded by whomever was using it. Elan Financial Services did not perform any of the most basic things every other credit card company does - send me my statements, alert me to exceeding my credit limit ( again, that wasn't actually me ), alert me to excessively large purchases being made, or alert me to suspicious activity.

There were several large charges supposedly from Systemic Formulas amounting to about {$2500.00} in a 2 week time period. That is a supplement company I use a lot for my business, which is why I didn't notice right away, but as it turns out these charges do not correspond to any orders I placed with Systemic Formulas. Nor does Systemic Formulas have any records of receiving those amounts. These are charges that were on the statements that had never been sent to me XXXX and I wasn't expecting statements as I wasn't using that card ). 
Throughout my investigations, I also found that on the XX/XX/XXXX statement that I had paid in full, there was already a fraudulent charge for {$1600.00} that I had paid, not realizing that this was fraud from Elan Financial Services. 
Despite Radius Global Solutions sending my file back to Elan Financial Services, Elan never reached out to me. 
I made many attempts to reach Elan Financial Services, I always ended up in never ending transferring loops and usually ended up in a dead end. My assistant tried. My lawyer tried. I sent them a fax on XXXX. In the fax, I was still willing to take on some of the financial responsibility, because I simply couldn't understand what had happened. Then I had investigated and found all the fraudulent charges done in the name of Systemic Formulas, etc. My lawyer mailed them letters, and made it very clear that I do not owe them and what they need to do to rectify this fraudulent situation. Even an employee at XXXX XXXX XXXX tried to help us, she got nowhere. We got no response from anyone. 
I also discovered that Elan had done many credit checks on me, but never reached out to me about any of the charges or unsent statements.

My lawyer referred me to a consumer protection lawyer. He took a look at everything and suggested if Elan Financial Services isn't doing anything to rectify any of it, to just leave it be as pursuing this would incur very high costs for me. While I found this highly concerning as fraud was committed against me, I had no other clear option. 
But then, on XXXX, I receive a debt collection letter from XXXX XXXX XXXX on behalf of Elan Financial Services for {$1400.00}. 
I called XXXX XXXX XXXX right away and informed them there had to be fraud as there was before, and they sent it back to Elan Financial Services. 
2 days later, Destiny in the fraud department of Elan Financial Services calls me, and explains I need to request the statements so I can specifically tell her which items are fraud. 
I called Card Member Services of Elan Financial Services as I was told, and was stuck in never ending transferring loops as each person told me they can't help me with that. XXXX even told me I can't make that request as my account is closed. Finally, someone in the legal department says she can help and places that request for my statements. She also updates my address, as each time I call the zip code I had to state was unclear. At times it was the original practice location zip code, then my old home zip code in Colorado, and then sometimes my current zip code. 
2 weeks later, I still had not received my requested statements. I tried calling XXXX in the fraud department of Elan several times, each time it went directly to her voicemail. At this point, her voicemail even says she's with the cardmember services and does not mention the fraud department anymore. She has not responded to my voicemails either. 
So I called cardmember services again. XXXX very politely kept me on hold for 30 minutes while trying to find someone to transfer me to who might be able to help ( I was just trying to find out about the status of my statement request ). She finally connected me with XXXX, who was exceptionally rude and after more time wasted, I was finally told to call the debt collection agency. This was surprising as they had already transferred my case back to Elan several weeks ago. 
I spoke with someone at XXXX XXXX XXXX again, and she was very apologetic and confused as my case had been sent back to them from Elan despite my telling them there is fraud. Instead of mailing me my statements so I can clarify the fraud, Elan Financial Services sent me back to debt collection. XXXX XXXX XXXX, knowing this is not correct, has asked me to wait for another 1 -2 weeks for them to find out how this could've happened. 
I'm attaching some of the documents, there are far more if needed.