Charge for Xfinity stream box

I have been charged $120 for an Xfinity Stream box after it taking months to get Xfinity to cancel service. I asked at the time what I needed to return and they said the modem only.  Now, I have a bill and can't locate a streaming box anywhere.  Not sure if the previous tenant tossed it or took it.  $120 seems outrageous for a streaming box that is several years old given Fire sticks and Roku's models go for under $50 and you can buy a Xumo streaming box (Xfinity type) for $60.