I must do supplementary exams, no one gets back.

I'm a registered student with Unisa for 2015 to complete one Module DAPM06S, I did submit my assignments and received my results that says supplementary exams. So I've contacted the no that says for further exams queries call ***, they said they can't assist me I must call the following no *** no answer, then they say I must try *** no answer, then againd I've tried *** I than again called *** no answer as well, so I decided to dial the George branch and they've tried, they also couldn't assist. All I want to know is how is it possible that they can say for any exam queries dial ***, but still no one can assist you, all I would like to know is am I gonna get the certificat or not, does this sound so difficult or what do they mean with with supplementary exams, because really I'm also a paying client or must I say student. I'm not studying by means of a bussary or sponsor, I'm paying out of my own pocket.