COMCAST CABLE in Florida forcing unwanted service on an elderly person Palatka Florida

My 71 year old relative with Demetia, got scammed into changing/ adding onto his internet service by a COMCAST customer service rep desperate for his comission. He only watches 4 channels. He was told they were raising the prices and he needs to change his selection. It went up to $175 a month, which he couldnt pay, so he discontinued service. He returned the box and everything else to the COMCAST location on Reid street, Palatka, FL. All bills were paid.

1 year later, he started getting collection bills and phone calls for outstanding payments due, tried to clarify, but COMCAST lied. Now the collection agencies heep harassing. There is NO money due.