Fucked my modem

Hello all, stupid user incoming!

I have a CenturyLink C200T wireless modem. Some time ago, I configured the admin username and password, and, true to form, didn't write it down. I write down all of my login info for everything else, but forgot one of the most important ones. Figures.

Anyways, I realized that there was no way to reset the username or password outside of a device factory reset, which I did. But when I go to the GUI with the defaults, it's telling me that I'm logging in with incorrect info. I've tried multiple times, in case I mistyped, but I get the same answer every time.

Where do I go from here?