Massive fluctuation of internet speed

I could not agree more to what everyone is saying. We watch Streaming TV on a smaller shared network that we have gone back and forth with for so long about how bad their service has gotten and now I feel pure embarrassed figuring out it is my internet. I checked it first and it would be great. But I found out if I checked it over and over, I would rarely ever get the same reading, like not even CLOSE.

I have asked and asked for assistance through our local store and they keep telling me they are letting the service dept know and it will be fixed but so far all it has done is get worse.  
Sometimes I can't even watch a show, much less a movie. It is night time, day time, middle of the night, doesn't matter. 
anybody figures out a solution, PLEASE PLEASE HELP!!