Can someone clarify whether an improper install (filter not installed that causes a pixalated picture (or sometimes freezing) and slow internet) is a "valid" reason to charge $60 for a technician to come out? Because the rep I just talked to wouldn't reverse my charge although: (1) i wasn't informed that I would be charged; and (2) the issue was nothing inside my house, but instead the missing filter outside. Instead, the Comcast rep simply kept saying that the $60 charge was "valid," as if somehow uttering "valid" gives Comcast a license to bill for bogus charges. Any insight would be well received. Thanks!