Problem Setting up New Wifi - Secondary User

I had this account made for me as a child under my parents' account nearly a decade ago, and had not used it in years. In the next month, I will be moving to an apartment that requires me to establish internet service with Comcast, so I attempted to sign in to this account to begin the purchase process. When I do so, however, I am met with the message that "as a secondary user, you cannot access restricted areas of My Account". This does not make any sense to me, as I am now the only user on my account and my parents are not listed, and it is preventing me from setting up internet.

When I have attempted any kind of troubleshooting, I am met with a litany of error messages that I am not the primary user.  When I attempt to visit https://idm.xfinity.com/myaccount/lookup?execution=e10s1 to look up who the primary user is, it does not work, perhaps because we no longer live at the original address the account was set up under. When I attempt to create a new account with my phone number or social security number, I am met with an error message. This is very frustating, as I would either like to get this problem addressed or be able to set up a new account so I can purchase wifi.

As of now, I am unable to do either and would appreciate guidance.