Laws aren't better than theories; they are generally statements about a narrow range of phenomena which can be expressed mathematically while a theory covers a wide range of phenomena. For example, theory explains the origin of all conservation laws in physics as being the result of symmetry. Each law covers a specific thing (i.e. conservation of momentum) while the theory covers all conserved quantities.

Every now-accepted physical law was once a theory - Newton, Kepler, Einstein, you name it