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

On XX/XX/2018, I was victim of a screen pop-up computer scam by a company claiming to be legitimate XXXX representatives, urged to call their number or whole computer and files would be deleted, etc. I fell for the scam, called them, and ultimately paid this bogus company " XXXX XXXX '' {$340.00} to 'fix ' the problem. I put that charge on my Discover Card. 
Next day, realizing I had indeed been scammed, I called Discover, cancelled the card used, and told them I would dispute any charge that came thru my account from this company. I got another card and new account number. 
The charge finally did show up after a few days, and I followed instructions from Billing Assistance to document the fraudulent scam and the actions I took to clear my computer, taking it to XXXX XXXX and paying for The XXXX XXXX to clean it and remove all XXXX XXXX-planted spyware and viruses. I sent all documentation from XXXX XXXX and a 3 page letter outlining what had happened during the phone call with XXXX XXXX to Billing Assistance via XXXX overnight mail on XX/XX/XXXX. It arrived at XXXX. XXXX XXXX in XXXX XXXX XXXX UT at XXXX XXXX on XXXX XXXX. 
A week later, however, I got an email saying my information had not arrived and if I didn't file it, my dispute would continue without it. I called immediately and spoke with a customer rep who told me she had no way of knowing if the information had arrived but that it took 10 days from the time it did arrive to get to the fraud squad. I accepted that. 
Another week later, a second email arrived saying my info had not arrived, etc. I called again, and was again told there was 1 ) no one to whom I could speak because it wasn't their department, 2 ) documentation took 10 days to reach the fraud department ( by now it had been 11 days since the info I mailed had arrived ) and 3 ) there was nothing further they could tell me. I faxed my documentation this time on XX/XX/2018. Still, there was no way to ascertain if it arrived. A customer service agent again said it would take 10 days for faxed information to get to the appropriate department in the dispute and there was no one who could help me. 
Then I got two emails sent within hours of each other saying that Discover had 'reviewed the information provided or that it was insufficient ' and they could not continue the dispute, finding in favor of the charge which was posted by a cover company, XXXX XXXX XXXX XXXX a Discover merchant company. I was invited to send in further documentation I have 'not yet shared with them ' and have 15 days from XX/XX/XXXX in which to do so. They consider the transaction valid and are notifying credit bureaus of my request to continue the dispute. I have no idea what documents of mine they used and why they were insufficient! XXXX XXXX records and a three page letter with names and techniques used seem not to have sufficed! Now Discover considers this dispute resolved! 
I will not pay these two illicit companies ... XXXX XXXX and its umbrella front, XXXX XXXX XXXX, with my Discover account, which is in excellent standing in every other way. 
I will continue to submit information to Discover, this time using the Scam description pages from the FTC website that word for word describe the scam perpetrated upon me, putting in my facts. 
I have filed a complaint against XXXX XXXX and its complicit company XXXX XXXX XXXX with the FTC. I am filing a complaint against Discover because it is not transparent in its communications with the customer nor internally. Someone should be able to tell a customer if and when documents have arrived! Someone should know, and 10 days to get it to the right fraud team seems excessive and also specious. 
Also, the emails claimed to have 'already reviewed my information ' while not explaining why it was insufficient. Nobody was available to answer my calls forwarded to the right departments by customer service agents. Discover has handled this shabbily and I am very upset with the outcome of my claim since it so clearly is a case of fraud by one of their merchants!