But, you haven't confirmed that is indeed unauthorized usage. It could merely be a fluke.
Post in the Direct forum before you go to the FCC and maybe someone can get this resolved quickly and easily.
Now, if you were threatened with service suspension or termination over this and had no other recourse, then I would see a complaint with the FCC would be warranted.
Employee of Charter Communications. The views and opinions expressed in the post above may not reflect those of my employer.