I am an animal groomer and I am looking for clipper blades that actually cut properly, suggestions?

I have bought dozens of blades through Andis and recently some Oster blades through PetEdge and they either do not cut through the hair, they cut the wrong length, or cut very unevenly. I've spoken with custer service to no avail and sharpening does not help. NEED BLADES, where to order and what kind!