Pixelation and freezing daily on multiple channels - Paying for unwatchable TV

Paying for unwatchable TV. I have been experiencing this issue for months. Have have an X1 DVR. I had not gotten around to returning our old one, so we decided to switch it out to see if that was the issue - it was not, same blocking, pixelating. Someone came out in January and tested my equipment and signal into my house and it was fine, so it is not an issue inside my house or with the equipment inside my house. He said it was a problem outside and he replaced something and things were okay, not perfect, for a few days. I was charged $70 for this so-called service call. 

Since then every single day on various channels all over the spectrum, we have trouble with freezing and blocking; it even affects the sound. We record shows on the DVR only to find out the signal blocked and pixelated constantly, so we can't watch the program. The problem is so bad at times, it is impossible to watch anything. I will also point out that I only have 1 DVR and one television so the signal should not be weak.  

We have reset the system and refreshed the signal and nothing fixes this issue. Xfinity must have a deeper issue in this area. I am paying for this service, so it should be working properly or I shouldn't be paying for it. If this doesn't get taken care of, I'm going to pay the extra fee to get out of my contract and take my business elsewhere.