Ivermectin is the standard medical intervention prescribed by the World Health Organization for the treatment of Human-Blackfly Onchocerciasis. This treatment is supposed to be administered twice yearly for between ten to fifteen years. This paper numerically examined the effect of unsuccessful treatment on transference dynamics of Human-Blackfly Onchocerciasis in the human society. The numerical study of the Human-Blackfly Onchocerciasis transmission model showed that the fraction of humans who exhaust their scheduled medical intervention as well as the proportionate transference of confirmed cases who unsuccessfully exhausted their medical intervention have important effect on the dynamics of Human-Blackfly Onchocerciasis in a population. Specifically, it was observed that a serious elevation in the fraction of humans who did not exhaust their standard medical intervention has serious effect on the backward bifurcation spectrum. Furthermore, it was again observed that in the process of boosting the rate of medical intervention of confirmed cases, it is also necessary to implement regulation strategies that would spur infected persons to endure the course of medical intervention and that the inability to sustain this will jeopardize the benefits of enhanced rates of medical intervention.