What's up with the constant "power outages"?

So here's the problem.  Several times a week the internet goes down for hours.  Work is lost because the "power outages" are sudden.  Every single time, the 800 customer service rep says it's a power outage.  After so many outages, our tech guys set up an appointment for Comcast to come out. The Comcast tech person replaced this part and that part, and finally today (after a couple of visits) replaced the node.  Hours later, the internet goes down again.  I called the 800 number and once again it is a power outage.  

I think what frustrates me the most is being told it's one thing, and then being told its' another.  The fact of the matter is, I am without service.  I have a small law office and rely 100% on Internet to run my business.  Even our phones are Internet phones. If comcast internet is down, my office is completely shut down. Of course I still have to pay my staff until the internet comes back up.  Given the number of "power outages", I have spent a lot of money paying staff for simply being present, while we wait for comcast to come back up. The frequency of these outages has now rendered comcast completely ineffective and costly.  

Truly, if it wasn't for the fact that comcast is the fastest internet available, and the only internet provider that is compatible with our systems, I would leave comcast in a heartbeat.  Terrible.