Unhappy with unisa

Hi unisa has been giving me so much problems... firstly i failed an assignment scl 1502 and they arent giving me any feedback as to where i went wrong and secondly they dont respond to any emails what so ever. I missed 1 of my exams as i fell ill and i ended up paying for the whole semester again because unisa doesnt respond to the emails that i have sent with my drs note attached. In the discussion forum most of the students have the same issue about the suplementary assignment for scl 1502 but we get no response. We are in September already and we still havent gotten any feedback as to what we are supposed to do. Please help our exams start in october