TV interference

After talking to a Comcast employee in my town I'm writing this. I'm 71 years old and on disability, could no longer afford all of Comcast so I dropped the tv service, kept internet and phone, bought an indoor antenna to watch tv. Some of the local channels are now being distorted and was told by this Comcast employee that Comcast can and will distort them through the WiFi. Why would a company do this? I could NO LONGER afford $221.00 dollars a month.