i had a problem with comcast speed/disconnection for quite awhile, they sent out the same "tv" technician 3-4 times and he always said my signals look fine, then they tried to tell me it was a pc issue without ever looking at my pc. it was not a pc issue because i am quite an expert at the windows operating system and i knew it was a problem on the ISP side, finally they sent out a real tech who found the problem without EVER stepping foot into my house, something wrong at the pole now im making them give me 2 months free while my service was crap.
so the point of my story is call them and tell them to send out a real tech, not a standard tech he will get to the bottom of the problem, even if it is on your pc they will find it