I cancelled my account but you guys keep charging me

I signed up for home internet service and while doing so, was essentially forced to accept your "Free Mobile" Promotion. I say forced because I told the representative multiple times that I didn't want the promotion but they insisted that I take it because it was "free". I had my suspicions about the free part and unfortunately my suspicions were proved correct.

The following month I received a $40 bill for the mobile phone/service that I never wanted. I reached out and was able to get that corrected. 

The same thing happened the following month. I reached out again, but this time I asked to cancel completely because I had the strange feeling that this was going to keep happening month after month. The rep kindly cancelled my mobile and said nothing needed to be done, except that I should drop my phone at the nearest xfinity to return. 

Which I did, however I was told that since it had been after 60 days that I could not return the phone. 

Obviously, I was frustrated. I never wanted this phone or service and now I'm stuck with this stupid phone that I haven't even turned off and that xfinity is telling me I can't even return. 

Of course, I could just pay the phone off outright for $140. 

Thanks a lot Xfinity, you guys are literally scammers.