Unable to access streaming on x1 box that I pay monthly for within your Internet

I pay a monthly fee for the x1 box for 8+ years now but I am not allowed to utilize the streaming apps because I switched Internet providers (just for cost it was cheaper I had no issues with Xfinity Internet) just got off the phone and they were no help. The gentleman at the store told me it shouldn't be an issue. I guess my main question is if I'm paying for this box why can I not use it to its full capabilities? Just because I don't have your Internet service anymore? Should I not be paying a lesser amount than for the box if I can't use all the features? 

I've been an Xfinity customer for over 20 years and I have slowly had to cancel services due to cost and and now because I had to save some money in the internet I have to go buy a fire stick or Roku to be able to access the streaming services I pay for separately. Even though I paid monthly for the box I can't use it fully with 3rd party Internet. Unfortunately this almost makes me want to completely get rid of your services entirely after 20 plus years 😔