Supersymmetry is actually a theory. Even a super beautiful one according to me. Starting from Noether's theorem and spin-statistics theorem, the most general mathematical structure you get is supersymmetry.
However, in supersymmetry, one still has a matter sector where the Standard Model fermions have scalar bosons (like the Higgs) partners, and a gauge sectors with the interactions, where gauge bosons have a fermionic partners.
Now, concrete realizations of supersymmetry are models. Those models predict observations that are not there... So that concrete supersymmetric realizations are more and more constrained by data, but not excluded yet. It will actually be impossible to fully exclude supersymmetry. Just to push it to higher and higher energy scales.