TV is Pixelated

I am a long time customer,  who is very dissatisfied with the comcast experience.  I live on Edgewood Avenue in SF,   TV is pixellated to a point we cannot watch. Technician came out, measured the signal, said it was ok and geve us a new box which was worse than ever, slow to change channels and all still pixellated.  He stated this was poor signal in street .. so why did we pay for nothing.  Furthermore, every time I call I cannot get a human being ,  just a recording who makes me re start the dame box every time .. which never works

I Dillon