Father passed away and overpaid monthly for several years and customer service keeps giving me the runaround about refund.

My father passed away in December 2025.  I am his personal rep/executor.  I canceled service via telephone with a representative 1/26/2026.  I then called back the next week because I was supposed to get an email to confirm that never came.  The representative assured me that the service had been disconnected and that a refund would be issued in 30 days.  30 days later I enter a chat with a representative and I am told that the account wasn't disconnected unfortunately but that they will make sure that it is and not to worry that the money that had been charged up until that point would be put back and the refund would be coming.  I went to Comcast store near me and the rep there said that service had still not been cancelled but he didn't know why but he cancelled it on March 3 and said that no managers were present at that time and to come back on March 5 to get the refund processed.  I went back March 5 and spent over an hour with the managers trying to get the start of a refund processed (the initial balance credit on his account when I cancelled in January was 1300 plus dollars).  One of the managers said someone hooked to the Wi-Fi after the date we cancelled so therefore we couldn't get a refund all the way back to the first time I cancelled- which is crazy- we were there cleaning out his house on multiple occasions and were unaware that the service was still there because I had called and cancelled it...... But that a refund notice would come to the email on the account (which is mine) or a prepaid card would be mailed to the address on record (which is forwarded to my address).  32 days later, I called and the representative said that she was speaking with the refund escalation team and that they said the credit will be sent to the original form of payment on the account.  I told her that my father had passed and that the form of payment used is no longer active and she said then they will mail you a check within 7 days.  How will they know to mail a check when she replied that immediately and did not like add a note to the account or anything.  So, I asked if I should call back in 7 days if I don't receive the check and she said yes.  So, I get off the phone and check my email, and I get several emails saying that unfortunately they cannot process the refund-no explanation as to why, just that they can't do it.  What recourse do I have here?  My father was very sick for the last few years of his life and did not realize he was overpaying (seems predatory).  Why should Xfinity be able to keep that money as opposed to it going to pay his end-of-life bills?  Who can I contact that will help -I have contacted by phone, chat, and at the store and all have assured me that the refund is coming.  Is there a customer service person who specializes in this?  Any help would be appreciated.