Pixelation, freezing with a side of sound distortion

I am in Connecticut and have been having pixelation and freezing issues for months. On channels such as FXX, SCI FI, Comedy Central, CBS, NBC, ABC, FOX. Xfinity sent a technician out after hours of troubleshooting and guess what....... same problem. Now they want me to try a wireless box. They keep trying to blame the wiring or connections and equipment.  New high quality cables.New equipment has all been tried and still have the same result. This problem has been happening for several years at random times but always those channels. WHEN IS XFINITY going to realize the problem is NOT on the customer end. After an hour of troubleshooting on the phone yesterday.I scheduled an appointment.

And then this morning they had the audacity to call me and tell me the problem was fixed. Guess what...... it is NOT fixed. 

Anyone else having these issues?