Cannot remove secondary account user OR unlink old account

In addition to being one of the lucky users that experience infinite account login loops so bad I had to turn off 2FA, it turns out I also get to have issues removing an old internet account from my Xfinity profile/user account. Yay.

I know how to unlink the account, so please don't just give me the click paths to get there. My problem is that every single time I go to unlink my old account, I am given some new reason for being unable to complete the process. First, it was that I had autopay on but no way to turn it off because my only active bill is for my new internet account (go figure). I had to contact support to turn autopay off for an inactive account which, while asinine, did work.

So, I go to unlink the account again and now it's telling me that I can't unlink the account because I'm the primary owner/user on the account. Okay.

But when I go to remove my sister as a secondary account user (since I assume that's why I'm getting this "primary" message), I just get a generic "Something went wrong" error and yet again I can't complete this very basic account management process. Contacting chat support to see if they could do it for me on the backend was unhelpful. Chat support kept trying to pawn me off on a random phone support line, which I don't like to use because you don't get anything in writing/on record when you do that.

Can someone please just help me get my old address off my account? We can start with removing my secondary account user to see if that lets me finally do it myself and go from there.