Product: Credit card or prepaid card

I applied for a credit card with Comerica Bank in XX/XX/2019 who and it ended up being a Elan Financial credit card not Comerica Bank. 
I was approved and received the card and began to use it without any problems. 
Then in XXXX I used a credit card authorization form to charge a {$8000.00} transaction with a {$10000.00} limit and was immediately called by Elans fraud protection to ask if I was trying to use the card for such a transaction. I told the representative that I was using the card and they asked the vendor name and the amount and I said yes that is me and I would like you to approve it so I can have them run the charge thru again. They said they cleared the system to know accept the charge and told me to call the vendor and run it thru again. 

I did just that and I immediately got a call from the fraud department again. I spoke to a supervisor and explained that I just got off the phone and your representative said this was taken care of and I would be able to run the card again and it would accept. So, the supervisor did a higher clearance for such a transaction ( the rep the first time should have know this ) and then the supervisor assured me to run it again. 
Guess what? It didnt go thru and again another call from the fraud dept. This went on four times in the same afternoon! Talk about incompetent people, well Elan Financial has them all. So, another supervisor ( a man - XXXX ) said she was again removing the alert to the system so it would be approved but then advised to run the card the next time to allow the system to reset after midnight. So, I thanked her and tried again the next morning and what do you think happened? It didnt work so I called again and spoke to another supervisor. She tried and told me to run it again and it didnt work. 
I then got another call ( how many are we up to now, 6? ) and  I didnt even bother to answer this time as I was fed up and couldnt deal with it anymore, so I used my XXXX card which was approved no problem. 

Then, the next day I called to complain and they told me they closed my account due to me making false statements on my account application or in the maintenance of my account which was current ( {$10000.00} limit with {$400.00} balance ) and payments made timely since receiving. Then they said my account is in danger of or is being used for fraud and that I will not live up to my obligations under the terms of the Card member Agreement which they never specifically identified. I asked specifically what false statements and of course they could not identify. Its all XXXX XXXX. How can it be fraud when I verified it was me using the card and they were trying to resolve and working with me and apologizing profusely for having this happen? 

Then I received the same letter from U.S Bank stating the following ; 'We 've conducted a review of your accounts and have reason to believe that you have made false statements on your account application or in the maintenance of your account, that your account is in danger of or is being used for fraud, and/or that you will not live up to your obligations under the terms of the cardmember agreement. As a result we are electing to exit our relationship in accordance with the terms of the cardmember agreement. ' I had two other cards with them for several year, one which Ive never used that was U.S Bank but must be affiliated with Elan since the letter has the same correspondence address. Then another letter for my 2nd Elan card I have that was in good standing, never missed a payment and had a $ XXXX limit with only $ XXXX used. They closed all three cards at same time stating same reason with same letter for all three. 

I've since retained a law firm to send a letter to get to the bottom of this and hold them accountable for taking away my livelihood of needed credit.