Why are we having problems with CBS broadcasts?

Why are we having problems with CBS broadcasts?

I have problems with pixalization from time to time.....pretty sure it's not my equipment...had service person out about a month ago...problem not resolve.

My dad ( 2 miles away ) is having the same problem
I get pixalization and then switch to another channel and it's OK.....
It can start to pixalate, then go to a LOCAL commercial and it'll be fine...then problem returns during national broadcast....
It's getting old....

How can i contact my local office to see if this is a ongoing problem with their equipment??