Netflix unauthorized profile

Xfinity -Netflix customer service

I am an xfinity customer with a xfinity access to Netflix.  I have some issue with unauthorized access to my Netflix.  Someone has established a Netflix profile with administrative  permission.  They are able to add additional profiles.  I can remove these additional profiles but I am not able to remove the original offending profile.  I cannot determine if they are able to actually use any Netflix services but the experience is aggravating and unsettling.  Using only the xfinity access to the Netflix account seems to limit my ability to remove the account and secondary security with text-

To phone authorization codes don’t seem to limit this offenders access to my Netflix profile administration.  I don’t think the offender is coming to my Netflix account through xfinity.

I am not sure what I can do to lock this person out of my Netflix account.  I have changed password on Xfinity, I have set secondary security via text access code, and I have placed an application pin code on the Xfinity access to my Netflix.  I need some help to remove the Netflix profile which I cannot remove