I actually received a response pretty quickly from the original agent. This time he tried to ask me if I perhaps am mistaken about the flight confirmation number. I just sent screenshots again of the boarding passes and the plane at the gate and mentioned that I had filed a DOT report and requested he find someone with the authority to credit my miles. At lear he somewhat got off the script I keep getting about not boarding. This time I also said something like do you realize that you are claiming I somehow came to airport and gate and got that new boarding pass and then did not fly and flew a different flight to get home?

Thank you for reaching back to Frontier Customer Relations. I see you mentioned that you did take the flight and you told us about the situations you experienced within the flight, however, looking at the records, I do see that XXXXX was marked as no show, at this point, we might be looking at two different flights possibly. Can you please confirm that we are talking about the confirmation code xxxxx or a different one?If so, please let us know, I will be glad to continue assisting.


Edit:

I did not write this in my reply but just thought of it. I should have added, do you think it's more likely that computer marking me as not boarded is somehow incorrect or I am lying after I gathered this screenshot of the new boarding pass and have the pic the plane. That I keep spending time over weeks to get credit for a flight that I did not fly?
Actually, after posting that I sent him another reply asking just what I wrote in the previous paragraph.