Xfinity mobile sent to collections

I have read many other posts with this same problem so it is not just me. My mother, who passed away in February 2023, was talked into getting an xfinity mobile phone in December 2022. Within a week or two she changed her mind, because she realized she wouldn't use it. I have a cellphone and take her everywhere so it would be a waste.  The phone was never turned on, and she returned the phone.  

In April I went to the x store and returned ALL the cable TV equipment  and asked for all services to be stopped except internet/wifi.  Never has anyone asked me about the phone or continuing mobile services. Then in May, I am logged into her account and something comes up about $26 cellphone bill that is overdue. So I began my chat and phonecall with xfinity mobile about the error. I was told it would be corrected and I should get a follow-up email. No, I never received that email.  

Yesterday I received a letter from collections asking for $204 for mobile phone. Please help me someone.