enquiry for visa

i'm a nationality of nigeria but i reside in southafrica and i got an admission to study in luzhou medical college, sichuan province, china. but i wasnt granted visa in the chinese embassey here in southafrica because my i dont have a permanent resident permit. please is it possible for me to forward my passport and all the relevant document(admission letter and JW202) via my relation in nigeria so that they can do the application of visa on my behalf? please help me with the relevant feedback. thanks. Josephine.