Xfinity asking me to return equipment that I never had

I am being constantly harassed with texts about returning nonexistent equipment I don't have. Every month now for months I have had to call and get a charge for this nonexistent equipment removed from my bill. I was assured at my last contact the issue was resolved, yet again I have received more harassment via text and the charge is not removed. I am assuming this problem is unsolvable and my only option is to terminate my relationship with Xfinity and get my internet elsewhere. Has anyone else had this issue? Xfinity is refusing to resolve it.