Five Representatives Could Not Resolve Basic Account Access Issue

I was trying to update the credit card on my account online, but Xfinity would not allow me to register my cell phone number because it says the number is connected to another account. You can't update credit card or payment info without a cell number on account. I discovered that my number appears to associated as a “member” on my own account. I tried deleting the member and also changing the access level to full access, but neither worked. Because I could not resolve the issue online, I called Xfinity. I paid my bill through the automated system and then asked for help fixing the cell phone/account-access problem. I was transferred to five different representatives. Each time, I had to verify my identity again and explain the issue from the beginning. None of them could resolve it. In the end, I was told I either have to wait for a PIN to arrive by mail or go to an Xfinity store. Not sure what I will do with a pin! This seems like an unnecessarily complicated process for a basic account issue, especially since I only had to call because I could not manage my payment information online in the first place.