If spinal cord has been severed in upper cervical region, spinal cord performs highly regulated functions.e.g: neuronal circuits in spinal cord that can cause:walking movements-reflexes that pull parts of the body away from painful objects correct?

This has been already answered, but in brief, once spinal cord is damaged, function below is destroyed. Spasticity can be present, but that is helpful only if strength is preserved. Reflex reactions to painful stimuli can occur, but this is part and parcel of the spasticity reactions. Complete severing of the cord, results in complete paralysis below level of damage.