Incorrectly Billed for Xfinity Mobile Services - New Mobile Line added without my consent- Billing dispute

On May 12, 2025 I received a bill for Xfinity Mobile Services.  I also have Xfinity Internet Service, so I missed this Mobile charge on my credit card. I currently have ATT cell phone service on 5 lines.  I have never had Xfinity Mobil Service for my cell phones.  I got bills each month that added to a total of $353.18.  I have reached out to Xfinity Support on more than 10 occasions to resolve this dispute.  I have been in the store on 6 occasions to work towards a resolution.  I have used chat feature more than 5 times.  Each time the Xfinity reps listens and understands and ensures me this will be taken care of and I will be reimbursed.  But, for some reason, they only reimburse a portion of the full refund.  The final amount that needs refunded is $47.53.  To summarize, I was billed a total of $353.18 by Xfinity Mobile and refunded a total of $305.65.  There is a $47.53 balance yet to be refunded back to my credit card on file.   Let me know if you can help?