Slow Speed Outside Normal Business Hours

Seems like my 200/20 business internet peters out frequently, often in the evening and outside support hours, all the way down to a tenth (or less) of the advertised speed.  I'm paying pretty handsomely for this package, and there have already been techs out here twice.  The wiring at the wall looks like a rat's nest.  Something needs to be done about this, and it seems there is no way to get ahold of anyone from Comcast who will actually do anything about it other than "Let's play the reboot game," and, "Well, do you have any splitters?" I'm considering ditching the business plan because it's no more reliable than Xfinity was, and much pricier for less speed. I rely on this service for serving several sites the need close to 24/7 uptime, and thus far I am not pleased with my investment in Comcast Business.