I used to have problems with my RR connection when the temperature dropped below a certain level in the winter time. I went through the same bullshit until they finally sent out a tech who didn't have his head burried up his anus. He replaced a splitter where the line came into my home and I haven't had a problem ever since.

Just like with your situation, I would tell them that I am losing my signal and they would tell me nothing was wrong. I even narrowed down the circumstances in which it happened and they still didn't listen. They are retards.