Cancel Xfinity Mobile Services

I have attempted to cancel my Xfinity Mobile service three times by calling the number provided by my local store and by visiting in person. I first called on September 25th and was assured my service was cancelled. I then received a bill on October 2nd and called again. During that call, I was told "to ignore the bill" and that my service had been cancelled.

I saw today it has not been cancelled, and I don't want to be chased by debt collectors for ignoring a charge. I then scheduled an in-person appointment to cancel, which is advertised on the Xfinity website as a valid option, but I was then shortly called by a manager who said they "don't do that in-person."

At this point, I would just like to cancel my mobile service. I never even inserted the SIM card.