double charged for xfinity month of May through June 2025

On June 19th 2025 I cancelled and returned my equipment, at that time I was told that they were going to issue a refund to my credit card because they already had charged my credit card for the following mount.  When I received my statements from Citi bank and US bank where they show that they had charged the same amount for the same period.  I went to Lancaster Xfinity office with all my statements and showed them that every payment was billed to my Citi bank card and I said why you are charging my other US bank credit card for the same month of May through June if you already received payment for the same amount and period on my Citi bank card.  I spoke to the manager in charge and she refused to acknowledge both payments of Citi bank and US bank for the same amount and for the same period.  I left the office disappointed because she could see the double charge on my two statements for the same period.  Before I went to the Lancaster office I had called Xfinity costumer support and they could not help me, I also went on line and I had the same negative result.  That is the reason why I am trying this forum hopefully I will have a better result.

[Edit: Personal Information]