Unfixed service and still want to be paid

I called support for weeks when I was having slow service.  Every time, I was told everything is fine.  No issues or outages.  You need to upgrade.  My response was; no, How will upgrade fix a slow and intermittent service?  If you cannot deliver the speed on the plan, how will you deliver on a faster speed.  It makes no sense.  After 3 or more weeks of this and still promises of it will be fixed. Nothing.

I finally cancelled my service, returned the equipment and now Xfinity wants me to pay for lack of service.  The worst customer service.  Cutting my speed down to get me to upgrade and never fixing the issue.  If fiber was in my neighborhood, I would go with utopia or some other service before Xfinity.