Ready to take legal action against this company

I have been charged $382.26 for the past year AFTER moving to a new home and new city. I cancelled my cable and ONLY transferred Internet. I  returned the equipment and I spoke to more people to resolve this issue than I can remember. I was told twice that I would be credited and the charges were stopped. I have been robbed by this company and I am now going to take serious legal action. Has anyone else ever been involved in this fraud by xfinity?