I had cancelled my Xfinity mobile account and I keep receiving messages of account closure

I had cancelled my mobile account. There was a final bill that was continuously being sent to my account. I have spoken with several account specialists in regard to cancelling my account and getting a courtesy credit for my last billing to finally close my account. The account never seems to get closed and I never receive a "final courtesy credit" to close my account. I had transferred my phone number after one month of using the Lifeline initiated phone number. I then had my phone number used with xfinity mobile transfered to my Lifeline mobile phone account. How can I finally close out my Xfinity mobile account permanently? 

For the record, the last rep I had spoken with was named Felix. Felix assured me that I would not owe anything and that my account would be properly closed. That was over two months ago.