Phone scam

For the third time, someone has ordered a new iPhone using my Xfinity account. The phones were actually shipped to me, and my credit cards are being charged for them.  I had to return them to the local Xfinity store along with a police report.  I was told that the bogus orders were placed by someone over the phone.  That's odd, because I can't even speak to an Xfinity rep without them sending me an authentication number to my phone, so I don't know how someone is able to purchase new phones without any security measures. I was told they used the credit card I have "on file". I'm trying to remove all cards on file, but the system won't let me. 

After the first two times, I changed the credit card that I had on file with Xfinity. This did not stop someone from ordering a third iPhone, on my account, which I am being charged for. 

We have spoken to Xfinity reps many times, and have been assured that these phones and related charges will be removed from my account.  However, when looking at my Xfinity account "devices" page, these fraudulent phones are still showing. 

This most recent time, I was on the phone with Xfinity for two and a half hours. In that time, I was transferred to four other departments.  Each time, they had to send me another verification code before they would speak with me, and I had to repeat all the details of my issue all over again. Nobody I spoke to seemed to have any idea on what they should do to resolve this, but all involved assured me that the issue would be taken care of, but so far nothing has changed.  I have since changed my Xfinity password, and I am attempting to turn off autopay and remove any credit cards from my account, but so far the Xfinity website will not allow me to turn off autopay.