The important thing to understand about supersymmetry (SUSY) is that in the most general case, there are approximately 105 new parameters. That's far too many to probe in a meaningful way, so most models choose between 2 and 5 to vary, and fix the rest. Then a bunch of models are chosen that hopefully cover a wide spread of different behaviors.
The true part is that several models have been excluded, basically as well as the LHC is going to be able to exclude/discover anything in the current energy regime. However, some of these models were just not chosen very well to begin with (but have historical importance) and others were chosen to have maximal signal strength.
So as time goes on, the search for SUSY turns away from "easy" models and looks at more complicated ones. With 105 parameters, there's a lot of parameter space unexplored.